diff --git a/src/backends/NetworkManagerDebian.c b/src/backends/NetworkManagerDebian.c
index 740572a..93c2914 100644
--- a/src/backends/NetworkManagerDebian.c
+++ b/src/backends/NetworkManagerDebian.c
@@ -37,6 +37,7 @@ #include "interface_parser.h"
 #include "nm-utils.h"
 
 #define ARPING "/usr/sbin/arping"
+#define RESOLVCONF "resolvconf"
 
 /*
  * nm_system_init
@@ -238,14 +239,14 @@ void nm_system_kill_all_dhcp_daemons (vo
 /*
  * nm_system_update_dns
  *
- * Make glibc/nscd aware of any changes to the resolv.conf file by
- * restarting nscd.
+ * Invalidate the nscd host cache, if it exists, since
+ * we changed resolv.conf.
  *
  */
 void nm_system_update_dns (void)
 {
-	nm_spawn_process ("/usr/sbin/invoke-rc.d nscd restart");
-
+	nm_info ("Clearing nscd hosts cache.");
+	nm_spawn_process ("/usr/sbin/nscd -i hosts");
 }
 
 
@@ -514,13 +515,60 @@ gboolean nm_system_device_get_use_dhcp (
 /*
  * nm_system_device_get_disabled
  *
- * Return whether the distro-specific system config tells us to use
- * dhcp for this device.
+ * Return whether the distro-specific system config tells us to disable 
+ * this device.
  *
  */
 gboolean nm_system_device_get_disabled (NMDevice *dev)
 {
-	return FALSE;
+	const char      *iface;
+	if_block	*curr_device, *curr_b;
+	if_data		*curr_d;
+	gboolean	 blacklist = TRUE;
+
+	g_return_val_if_fail (dev != NULL, TRUE);
+
+	iface = nm_device_get_iface (dev);
+
+	ifparser_init ();
+
+	/* If the device is listed in a mapping, do not control it */
+	if (ifparser_getmapping (iface) != NULL) {
+		blacklist = TRUE;
+		goto out;
+	}
+
+	/* If the interface isn't listed in /etc/network/interfaces then
+	 * it's considered okay to control it.
+ 	 */
+	curr_device = ifparser_getif (iface);
+	if (curr_device == NULL) {
+		blacklist = FALSE;
+		goto out;
+	}
+
+	/* If the interface is listed and isn't marked "auto" then it's
+	 * definitely not okay to control it.
+	 */
+	for (curr_b = ifparser_getfirst (); curr_b; curr_b = curr_b->next) {
+		if ((!strcmp (curr_b->type, "auto") || !strcmp (curr_b->type, "allow-hotplug"))
+		    && strstr (curr_b->name, iface))
+			blacklist = FALSE;
+	}
+
+	/* If the interface has no options other than just "inet dhcp"
+	 * it's probably ok to fiddle with it. 
+	 */
+	for (curr_d = curr_device->info; curr_d; curr_d = curr_d->next) {
+		if (strcmp (curr_d->key, "inet")
+		    || strcmp (curr_d->data, "dhcp" ))
+			blacklist = TRUE;
+	}
+
+out:
+	ifparser_destroy ();
+
+	return blacklist;
 }
 
 
@@ -563,12 +611,18 @@ gboolean nm_system_deactivate_dialup (GS
 		if (strcmp (dialup, config->name) == 0)
 		{
 			char *cmd;
+			int status;
 
 			nm_info ("Deactivating dialup device %s (%s) ...", dialup, (char *) config->data);
 			cmd = g_strdup_printf ("/sbin/ifdown %s", (char *) config->data);
 			nm_spawn_process (cmd);
 			g_free (cmd);
-			ret = TRUE;
+			if (status == 0) {
+				ret = TRUE;
+			} else {
+				nm_warning ("Couldn't deactivate dialup device %s (%s) - %d", dialup, (char *) config->data, status);
+				ret = FALSE;
+			}
 			break;
 		}
 	}
@@ -587,12 +641,18 @@ gboolean nm_system_activate_dialup (GSLi
 		if (strcmp (dialup, config->name) == 0)
 		{
 			char *cmd;
+			int status;
 
 			nm_info ("Activating dialup device %s (%s) ...", dialup, (char *) config->data);
 			cmd = g_strdup_printf ("/sbin/ifup %s", (char *) config->data);
 			nm_spawn_process (cmd);
 			g_free (cmd);
-			ret = TRUE;
+			if (status == 0) {
+				ret = TRUE;
+			} else {
+				nm_warning ("Couldn't activate dialup device %s (%s) - %d", dialup, (char *) config->data, status);
+				ret = FALSE;
+			}
 			break;
 		}
 	}
@@ -603,23 +663,26 @@ gboolean nm_system_activate_dialup (GSLi
 GSList * nm_system_get_dialup_config (void)
 {
 	const char *buf;
-	unsigned int i = 0;
+	const char *provider;
 	GSList *list = NULL;
 	if_block *curr;
 	ifparser_init();
 
 	/* FIXME: get all ppp(and others?) lines from /e/n/i here */
 	curr = ifparser_getfirst();
-	while(curr!=NULL)
+	while (curr != NULL)
 	{
 		NMDialUpConfig *config;
-		if (strcmp(curr->type,"iface")==0) 
+		if (strcmp(curr->type, "iface") == 0) 
 		{
-			buf = ifparser_getkey(curr,"inet");
-			if (buf && strcmp (buf, "ppp")==0)
+			buf = ifparser_getkey(curr, "inet");
+			if (buf && strcmp (buf, "ppp") == 0)
 			{
+				provider = ifparser_getkey(curr, "provider");
+				if (!provider) 
+					provider = "default provider";
 				config = g_malloc (sizeof (NMDialUpConfig));
-				config->name = g_strdup_printf ("Modem (#%d)", i++);
+				config->name = g_strdup_printf ("%s via Modem", provider);
 				config->data = g_strdup (curr->name);	/* interface name */
 
 				list = g_slist_append (list, config);
@@ -631,14 +694,6 @@ GSList * nm_system_get_dialup_config (vo
 	}
 	ifparser_destroy();
 
-	/* Hack: Go back and remove the "(#0)" if there is only one device */
-	if (i == 1)
-	{
-		NMDialUpConfig *config = (NMDialUpConfig *) list->data;
-		g_free (config->name);
-		config->name = g_strdup ("Modem");
-	}
-
 	return list;
 }
 
@@ -679,7 +734,10 @@ void nm_system_set_hostname (NMIP4Config
  */
 gboolean nm_system_should_modify_resolv_conf (void)
 {
-	return TRUE;
+	if (g_find_program_in_path(RESOLVCONF) != NULL)
+		return FALSE;
+	else
+		return TRUE;
 }
 
 
diff --git a/src/backends/interface_parser.c b/src/backends/interface_parser.c
index 53d6487..b3ad300 100644
--- a/src/backends/interface_parser.c
+++ b/src/backends/interface_parser.c
@@ -50,11 +50,13 @@ void add_block(const char *type, const c
 
 void add_data(const char *key,const char *data)
 {
+	if_data *ret;
+
 	// Check if there is a block where we can attach our data
 	if (first == NULL)
 		return;
 			
-	if_data *ret = (if_data*)calloc(1,sizeof(struct _if_data));
+	ret = (if_data*) calloc(1,sizeof(struct _if_data));
 	ret->key = g_strdup(key);
 	ret->data = g_strdup(data);
 	
@@ -71,14 +73,18 @@ void add_data(const char *key,const char
 	//printf("added data '%s' with key '%s'\n",data,key);
 }
 
-#define SPACE_OR_TAB(string,ret) {ret = strchr(string,' ');ret=(ret == NULL?strchr(string,'\t'):ret);}
+// define what we consider a whitespace
+#define WS " \t"
 
 void ifparser_init(void)
 {
 	FILE *inp = fopen(INTERFACES,"r");
 	int ret = 0;
+	int pos;
+	int len;
 	char *line;
-	char *space;
+	char *key;
+	char *data;
 	char rline[255];
 
 	if (inp == NULL)
@@ -89,7 +95,7 @@ void ifparser_init(void)
 	first = last = NULL;
 	while(1)
 	{
-		line = space = NULL;
+		line = NULL;
 		ret = fscanf(inp,"%255[^\n]\n",rline);
 		if (ret == EOF)
 			break;
@@ -102,50 +108,71 @@ void ifparser_init(void)
 		line = rline;
 		while(line[0] == ' ')
 			line++;
-		if (line[0]=='#' || line[0]=='\0')
+		if (line[0] == '#' || line[0] == '\0')
 			continue;
 		
-		SPACE_OR_TAB(line,space)
-		if (space == NULL)
+		len = strlen(line);
+		pos = 0;
+		while (!strchr(WS, line[pos]) && pos < len) pos++;
+
+		// terminate key string and skip further whitespaces
+		line[pos++] = '\0';
+		while (strchr(WS, line[pos]) && pos < len) pos++;
+
+		if (pos >= len)
 		{
-			nm_warning ("Error: Can't parse interface line '%s'\n",line);
+			nm_warning ("Error: Can't parse line '%s'\n", line);
 			continue;
 		}
-		space[0] = '\0';
-		
+		key = &line[0];
+		data = &line[pos];
+
 		// There are four different stanzas:
 		// iface, mapping, auto and allow-*. Create a block for each of them.
-		if (strcmp(line,"iface")==0)
+		if (strcmp(key, "iface") == 0)
 		{
-			char *space2 = strchr(space+1,' ');
-			if (space2 == NULL)
+			char *key2;
+
+			while (!strchr(WS, line[pos]) && pos < len ) pos++;
+
+			// terminate first data string and skip further whitespaces
+			line[pos++] = '\0';
+			while (strchr(WS, line[pos]) && pos < len) pos++;
+			if (pos >= len)
 			{
-				nm_warning ("Error: Can't parse iface line '%s'\n",space+1);
+				nm_warning ("Error: Can't parse iface line '%s'\n", data);
 				continue;
 			}
-			space2[0]='\0';
-			add_block(line,space+1);
+			key2 = &line[pos];
+			
+			add_block(key, data);
 
-			if (space2[1]!='\0')
+			if (pos < len)
 			{
-				space = strchr(space2+1,' ');
-				if (space == NULL)
+				
+				while (!strchr(WS, line[pos]) && pos < len ) pos++;
+
+				// terminate key2 string and skip further whitespaces
+				line[pos++] = '\0';
+				while (strchr(WS, line[pos]) && pos < len) pos++;
+				if (pos >= len)
 				{
-					nm_warning ("Error: Can't parse data '%s'\n",space2+1);
+					nm_warning ("Error: Can't parse inet line '%s'\n", key2);
 					continue;
 				}
-				space[0] = '\0';
-				add_data(space2+1,space+1);
+				data = &line[pos];
+
+				add_data(key2, data);
 			}
 		}
-		else if (strcmp(line,"auto")==0)
-			add_block(line,space+1);
-		else if (strcmp(line,"mapping")==0)
-			add_block(line,space+1);
-		else if (strncmp(line,"allow-",6)==0)
-			add_block(line,space+1);
+		else if (strcmp(key, "auto") == 0)
+			add_block(key, data);
+		else if (strcmp(key, "mapping") == 0)
+			add_block(key, data);
+		else if (strncmp(key, "allow-", 6) == 0)
+			add_block(key, data);
 		else
-			add_data(line,space+1);
+			add_data(key, data);
 		
 		//printf("line: '%s' ret=%d\n",rline,ret);
 	}
@@ -198,6 +225,18 @@ if_block *ifparser_getif(const char* ifa
 	return NULL;
 }
 
+if_block *ifparser_getmapping(const char* iface)
+{
+	if_block *curr = first;
+	while(curr!=NULL)
+	{
+		if (strcmp(curr->type,"mapping")==0 && strcmp(curr->name,iface)==0)
+			return curr;
+		curr = curr->next;
+	}
+	return NULL;
+}
+
 const char *ifparser_getkey(if_block* iface, const char *key)
 {
 	if_data *curr = iface->info;
diff --git a/src/backends/interface_parser.h b/src/backends/interface_parser.h
index 075f454..8914283 100644
--- a/src/backends/interface_parser.h
+++ b/src/backends/interface_parser.h
@@ -44,6 +44,7 @@ void ifparser_init(void);
 void ifparser_destroy(void);
 
 if_block *ifparser_getif(const char* iface);
+if_block *ifparser_getmapping(const char* iface);
 if_block *ifparser_getfirst(void);
 const char *ifparser_getkey(if_block* iface, const char *key);