User-Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X 10.4; en-US; rv:1.9.2.10) Gecko/20100914 Firefox/3.6.10 FirePHP/0.4 Build Identifier: Mozilla/5.0 (Macintosh; U; PPC Mac OS X 10.4; en-US; rv:1.9.2.10) Gecko/20100914 Firefox/3.6.10 FirePHP/0.4 When you select the drop-down list, the browser crashes. I have used the Jquery plugin Uniform (http://pixelmatrixdesign.com/uniform/) to style the form elements but this seems to crash the browser. I have checked on Safari and it worked ok. IE on mac and PC was fine. Chrome was a bit jittery but still worked. Firefox 3.6.10 on PC just didn't show the list. Only Mac Firefox seemed to crash the browser. Reproducible: Always Steps to Reproduce: 1.Load the page http://sbgi.tapdev.co.uk/events/content/179/utility_street_works 2.Select any of the drop-down lists under the heading `Utility Metering` Actual Results: The browser should crash Expected Results: The list of products should be displayed I am using jquery to check the state of the drop-down, to enable the add to order button. I am also using a flowplayer plugin called overlay but this is not working on the drop-down lists but on the share button

firefox-bin[72890:813] *** Assertion failure in -[NSNextStepFrame lockFocus], /SourceCache/AppKit/AppKit-949.54/AppKit.subproj/NSView.m:4755 firefox-bin[72890:813] Mozilla has caught an Obj-C exception [NSInternalInconsistencyException: -[NSNextStepFrame(0x21e7dd00) lockFocus] failed with window=0x21e7dc60, windowNumber=9586, [self isHiddenOrHasHiddenAncestor]=0] firefox-bin[72890:813] Generating stack trace for Obj-C exception... (gdb) bt #0 0x91d09266 in mach_msg_trap () #1 0x91d10a5c in mach_msg () #2 0x93a7ee7e in CFRunLoopRunSpecific () #3 0x93a7faa8 in CFRunLoopRunInMode () #4 0x91538300 in -[NSConcreteTask waitUntilExit] () #5 0x12741db3 in nsObjCExceptionLog (aException=0x21e52720) at nsObjCExceptions.h:129 #6 0x12746e93 in nsCocoaWindow::Show (this=0x21e7dbb0, bState=1) at widget/src/cocoa/nsCocoaWindow.mm:696 #7 0x12f8543a in nsView::NotifyEffectiveVisibilityChanged (this=0x21f299a0, aEffectivelyVisible=1) at view/src/nsView.cpp:510 #8 0x12f854bd in nsView::SetVisibility (this=0x21f299a0, aVisibility=nsViewVisibility_kShow) at view/src/nsView.cpp:529 #9 0x12f893cb in nsViewManager::SetViewVisibility (this=0x2202ee10, aView=0x21f299a0, aVisible=nsViewVisibility_kShow) at view/src/nsViewManager.cpp:1386 #10 0x129b9ddd in nsComboboxControlFrame::ShowPopup (this=0x1bee9048, aShowPopup=1) at layout/forms/nsComboboxControlFrame.cpp:365 #11 0x129b9fa2 in nsComboboxControlFrame::ShowList (this=0x1bee9048, aShowList=1) at layout/forms/nsComboboxControlFrame.cpp:389 #12 0x129ba252 in nsComboboxControlFrame::ShowDropDown (this=0x1bee9048, aDoDropDown=1) at layout/forms/nsComboboxControlFrame.cpp:740 #13 0x129d66ef in nsListControlFrame::MouseDown (this=0x1bee9168, aMouseEvent=0x22f0f5f0) at layout/forms/nsListControlFrame.cpp:2241 #14 0x129d678f in nsListEventListener::MouseDown (this=0x21f2aed0, aEvent=0x22f0f5f0) at layout/forms/nsListControlFrame.cpp:2810 #15 0x12d7d662 in DispatchToInterface (aEvent=0x22f0f5f0, aListener=0x21f2aed4, aMethod={__pfn = 0x11, __delta = 0}, aIID=@0x136f3e4c) at content/events/src/nsEventListenerManager.cpp:175 ...

It also crashes a recent mozilla-central debug build on OSX. It does not crash on Windows or Linux64, but the dropdown menu does not appear when clicking the combobox.

I can also easily reproduce this, in FF 3.10 on OS X 10.5.8. This bug is a dup of bug 550392, but has much better steps-to-reproduce.