--- a/src/gui/image/qbmphandler.cpp	Fri Feb 19 23:40:16 2010 +0200
+++ b/src/gui/image/qbmphandler.cpp	Fri Mar 12 15:46:37 2010 +0200
@@ -144,7 +144,7 @@
 static int calc_shift(int mask)
 {
     int result = 0;
-    while (!(mask & 1)) {
+    while (mask && !(mask & 1)) {
         result++;
         mask >>= 1;
     }