Index: /trunk/src/org/openstreetmap/josm/gui/mappaint/MapImage.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/mappaint/MapImage.java	(revision 8102)
+++ /trunk/src/org/openstreetmap/josm/gui/mappaint/MapImage.java	(revision 8103)
@@ -69,5 +69,5 @@
             disabledImgCache = (BufferedImage) disImg;
         } else {
-            disabledImgCache = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_BYTE_GRAY);
+            disabledImgCache = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_ARGB);
             Graphics g = disabledImgCache.getGraphics();
             g.drawImage(disImg, 0, 0, null);