--- original-bwidget-1.9.6/mainframe.tcl	2011-05-25 16:10:07.000000000 +0100
+++ patched-bwidget-1.9.6/mainframe.tcl	2013-06-11 18:09:11.000000000 +0100
@@ -203,7 +203,8 @@
 
     # The ttk frame has no -background
     if {![Widget::theme] && [Widget::hasChanged $path -background bg] } {
-	if {$::tcl_platform(platform) == "unix"} {
+	if {$::tcl_platform(platform) == "unix"
+	     && [tk windowingsystem] ne "aqua"} {
 	    set listmenu [$_widget($path,top) cget -menu]
 	    while { [llength $listmenu] } {
 		set newlist {}
