Index: kcontrol/displayconfig/displayconfig.cpp
===================================================================
--- kcontrol/displayconfig/displayconfig.cpp	(revision 1251243)
+++ kcontrol/displayconfig/displayconfig.cpp	(working copy)
@@ -614,14 +614,18 @@
 void KDisplayConfig::moveMonitor(DraggableMonitor* monitor, int realx, int realy) {
 	int i;
 	int j;
+	bool primary_found;
 	DraggableMonitor *primary_monitor;
 	SingleScreenData *screendata;

 	// Find the primary monitor
+	primary_found = false;
 	for (i=0;i<numberOfScreens;i++) {
 		screendata = m_screenInfoArray.at(i);
-		if (screendata->is_primary)
+		if (screendata->is_primary) {
 			j=i;
+			primary_found = true;
+		}
 	}
 	TQObjectList monitors = base->monitorPhyArrange->childrenListObject();
 	if ( monitors.count() ) {
@@ -634,13 +638,15 @@
 		}
 	}

-	int tx = realx * base->monitorPhyArrange->resize_factor;
-	int ty = realy * base->monitorPhyArrange->resize_factor;
-
-	if (!monitor->isHidden())
-		monitor->move((base->monitorPhyArrange->width()/2)-(primary_monitor->width()/2)+tx,(base->monitorPhyArrange->height()/2)-(primary_monitor->height()/2)+ty);
-	else
-		monitor->move(base->monitorPhyArrange->width(), base->monitorPhyArrange->height());
+	if (primary_found && primary_monitor) {
+		int tx = realx * base->monitorPhyArrange->resize_factor;
+		int ty = realy * base->monitorPhyArrange->resize_factor;
+
+		if (!monitor->isHidden())
+			monitor->move((base->monitorPhyArrange->width()/2)-(primary_monitor->width()/2)+tx,(base->monitorPhyArrange->height()/2)-(primary_monitor->height()/2)+ty);
+		else
+			monitor->move(base->monitorPhyArrange->width(), base->monitorPhyArrange->height());
+	}
 }

 // int KDisplayConfig::realResolutionSliderValue() {