diff --git a/drivers/isimodem/network-registration.c b/drivers/isimodem/network-registration.c
index 23edf49a..02e2991d 100644
--- a/drivers/isimodem/network-registration.c
+++ b/drivers/isimodem/network-registration.c
@@ -264,10 +264,8 @@ static void isi_registration_status(struct ofono_netreg *netreg,
 		return;
 
 error:
-	if (cbd)
-		g_free(cbd);
-
 	CALLBACK_WITH_FAILURE(cb, -1, -1, -1, -1, data);
+	g_free(cbd);
 }
 
 static bool name_get_resp_cb(GIsiClient *client, const void *restrict data,
@@ -663,16 +661,16 @@ static void rat_ind_cb(GIsiClient *client, const void *restrict data,
 		case NET_RAT_INFO: {
 			guint8 info = 0;
 
-			if (!g_isi_sb_iter_get_byte(&iter, &nd->rat, 2))
+			if (!g_isi_sb_iter_get_byte(&iter, &nd->rat, 2)
+				|| !g_isi_sb_iter_get_byte(&iter, &info, 3))
 				return;
 
-			if (!g_isi_sb_iter_get_byte(&iter, &info, 3))
-				return;
+			if (info) {
 
-			if (info)
 				if (!g_isi_sb_iter_get_byte(&iter,
 							&nd->gsm_compact, 4))
 					return;
+			}
 			break;
 		}
 
@@ -769,7 +767,8 @@ static bool rssi_resp_cb(GIsiClient *client, const void *restrict data,
 		return false;
 
 	if (msg[1] != NET_CAUSE_OK) {
-		DBG("Request failed: %s", net_isi_cause_name(msg[1]));
+		DBG("Request failed: %s (0x%02X)",
+			net_isi_cause_name(msg[1]), msg[1]);
 		goto error;
 	}
 
diff --git a/drivers/isimodem/phonebook.c b/drivers/isimodem/phonebook.c
index 12a2c15a..314babcf 100644
--- a/drivers/isimodem/phonebook.c
+++ b/drivers/isimodem/phonebook.c
@@ -292,7 +292,7 @@ static void reachable_cb(GIsiClient *client, bool alive, uint16_t object,
 		return;
 	}
 
-	DBG("%s (v.%03d.%03d) reachable",
+	DBG("%s (v%03d.%03d) reachable",
 		pn_resource_name(g_isi_client_resource(client)),
 		g_isi_version_major(client),
 		g_isi_version_minor(client));
diff --git a/drivers/isimodem/voicecall.c b/drivers/isimodem/voicecall.c
index 4c70c12a..90106ee0 100644
--- a/drivers/isimodem/voicecall.c
+++ b/drivers/isimodem/voicecall.c
@@ -1310,7 +1310,7 @@ static void isi_call_verify_cb(GIsiClient *client,
 		return;
 	}
 
-	DBG("%s (v.%03d.%03d) reachable",
+	DBG("%s (v%03d.%03d) reachable",
 		pn_resource_name(g_isi_client_resource(client)),
 		g_isi_version_major(client),
 		g_isi_version_minor(client));
@@ -1347,8 +1347,6 @@ static void isi_voicecall_remove(struct ofono_voicecall *call)
 {
 	struct isi_voicecall *data = ofono_voicecall_get_data(call);
 
-	DBG("");
-
 	if (data) {
 		g_isi_client_destroy(data->client);
 		g_free(data);