It is a residual crash signature that exists in 3.6 and the trunk, but there is a spike in crashes from 4.0b11pre/20110131. It is #27 top crasher in 4.0b11. Signature nsBidiPresUtils::RemoveBidiContinuation(nsIFrame*, int, int, int&) UUID a6231c45-3874-4d8d-8318-042472110208 Time 2011-02-08 23:54:44.919861 Uptime 10077 Install Age 77144 seconds (21.4 hours) since version was first installed. Product Firefox Version 4.0b12pre Build ID 20110207030345 Branch 2.0 OS Windows NT OS Version 6.1.7600 CPU x86 CPU Info GenuineIntel family 6 model 23 stepping 10 Crash Reason EXCEPTION_ACCESS_VIOLATION_READ Crash Address 0xfffffffff0de812f User Comments App Notes AdapterVendorID: 1002, AdapterDeviceID: 9553, AdapterDriverVersion: 8.56.1.15 Frame Module Signature [Expand] Source 0 xul.dll nsBidiPresUtils::RemoveBidiContinuation layout/base/nsBidiPresUtils.cpp:1217 1 xul.dll nsBidiPresUtils::Resolve layout/base/nsBidiPresUtils.cpp:531 2 xul.dll nsBlockFrame::Reflow 3 xul.dll nsBlockReflowContext::ReflowBlock layout/generic/nsBlockReflowContext.cpp:297 4 xul.dll nsBlockFrame::ReflowBlockFrame layout/generic/nsBlockFrame.cpp:3184 5 xul.dll nsBlockFrame::ReflowLine layout/generic/nsBlockFrame.cpp:2506 6 xul.dll nsBlockFrame::ReflowDirtyLines layout/generic/nsBlockFrame.cpp:1999 7 xul.dll nsBlockFrame::Reflow layout/generic/nsBlockFrame.cpp:1080 8 xul.dll nsBlockReflowContext::ReflowBlock layout/generic/nsBlockReflowContext.cpp:297 9 xul.dll nsBlockFrame::ReflowBlockFrame layout/generic/nsBlockFrame.cpp:3184 10 xul.dll nsBlockFrame::ReflowLine layout/generic/nsBlockFrame.cpp:2506 11 xul.dll nsBlockFrame::ReflowDirtyLines layout/generic/nsBlockFrame.cpp:1999 12 xul.dll nsBlockFrame::Reflow layout/generic/nsBlockFrame.cpp:1080 13 xul.dll nsContainerFrame::ReflowChild layout/generic/nsContainerFrame.cpp:740 14 xul.dll nsCanvasFrame::Reflow layout/generic/nsCanvasFrame.cpp:494 15 xul.dll nsContainerFrame::ReflowChild layout/generic/nsContainerFrame.cpp:740 16 xul.dll nsHTMLScrollFrame::ReflowScrolledFrame layout/generic/nsGfxScrollFrame.cpp:533 17 xul.dll nsHTMLScrollFrame::ReflowContents layout/generic/nsGfxScrollFrame.cpp:625 18 xul.dll nsHTMLScrollFrame::Reflow layout/generic/nsGfxScrollFrame.cpp:866 19 xul.dll nsContainerFrame::ReflowChild layout/generic/nsContainerFrame.cpp:740 20 xul.dll ViewportFrame::Reflow layout/generic/nsViewportFrame.cpp:293 21 xul.dll PresShell::DoReflow layout/base/nsPresShell.cpp:7849 22 xul.dll PresShell::ProcessReflowCommands layout/base/nsPresShell.cpp:7988 23 xul.dll PresShell::FlushPendingNotifications layout/base/nsPresShell.cpp:4897 24 xul.dll nsDocument::FlushPendingNotifications content/base/src/nsDocument.cpp:6448 25 xul.dll nsGenericElement::GetPrimaryFrame content/base/src/nsGenericElement.cpp:3761 26 xul.dll nsGenericElement::GetStyledFrame content/base/src/nsGenericElement.cpp:1479 27 xul.dll nsGenericHTMLElement::GetOffsetRect content/html/content/src/nsGenericHTMLElement.cpp:512 28 xul.dll nsGenericHTMLElement::GetOffsetHeight content/html/content/src/nsGenericHTMLElement.cpp:655 29 xul.dll nsIDOMNSHTMLElement_GetOffsetHeight obj-firefox/js/src/xpconnect/src/dom_quickstubs.cpp:20774 30 mozjs.dll js::Shape::get js/src/jsscopeinlines.h:264 31 mozjs.dll js_GetProperty js/src/jsobj.cpp:5454 32 mozjs.dll js::mjit::ic::GetProp js/src/methodjit/PolyIC.cpp:1692 33 mozjs.dll js::CopyInitializerObject js/src/jsobjinlines.h:1169 34 mozjs.dll js::mjit::stubs::NewInitObject js/src/methodjit/StubCalls.cpp:1314 35 xul.dll xpcObjectHelper::~xpcObjectHelper 36 mozjs.dll js::mjit::EnterMethodJIT js/src/methodjit/MethodJIT.cpp:748 37 mozjs.dll CheckStackAndEnterMethodJIT js/src/methodjit/MethodJIT.cpp:774 38 mozjs.dll js::mjit::JaegerShot js/src/methodjit/MethodJIT.cpp:791 39 mozjs.dll js::RunScript js/src/jsinterp.cpp:637 40 mozjs.dll js::Invoke js/src/jsinterp.cpp:720 41 mozjs.dll js::ExternalInvoke js/src/jsinterp.cpp:841 42 mozjs.dll JS_CallFunctionValue js/src/jsapi.cpp:5048 43 xul.dll nsXPCWrappedJSClass::CallMethod js/src/xpconnect/src/xpcwrappedjsclass.cpp:1701 44 xul.dll nsXPCWrappedJS::CallMethod js/src/xpconnect/src/xpcwrappedjs.cpp:588 45 xul.dll PrepareAndDispatch xpcom/reflect/xptcall/src/md/win32/xptcstubs.cpp:114 46 xul.dll SharedStub xpcom/reflect/xptcall/src/md/win32/xptcstubs.cpp:141 47 xul.dll nsEventListenerManager::HandleEventSubType content/events/src/nsEventListenerManager.cpp:1127 A possible regression range for the spike could be: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=336d5906cb0f&tochange=732a38102733 More reports at: https://crash-stats.mozilla.com/report/list?range_value=4&range_unit=weeks&signature=nsBidiPresUtils%3A%3ARemoveBidiContinuation%28nsIFrame*%2C%20int%2C%20int%2C%20int%26%29

Bug 635329 has a testcase that causes a crash with the same signature.

No crashes on crash-stats with build ID later than 2011-02-21 - fixed by bug 635329