--- gui.tcl.old	2009-01-12 23:35:52.000000000 +0400
+++ gui.tcl	2009-01-12 23:34:37.000000000 +0400
@@ -832,7 +832,10 @@
 		set oldgrab ""
 		if { $modal } {
 			set oldgrab [grab current]
-			grab set $w
+			# Another application has grab! Keep trying until grab succeeds
+			while {[catch {grab set $w}]} {
+				after 100
+			}
 		}
 
 		tkwait variable customMessageBoxAnswerTracker($uniqueId)