Index: trunk/src/org/openstreetmap/josm/data/osm/visitor/MapPaintVisitor.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/osm/visitor/MapPaintVisitor.java	(revision 633)
+++ trunk/src/org/openstreetmap/josm/data/osm/visitor/MapPaintVisitor.java	(revision 634)
@@ -404,5 +404,5 @@
 
 		Rectangle screen = g.getClipBounds();
-		if (screen.contains(x,y)) {
+		if ((screen != null) && screen.contains(x,y)) {
 			Color c = g.getColor();
 			g.setColor(backgroundColor);