It is a new crash signature that was introduced by 4.0b8pre/20101203 build. It is #12 top crasher in this build. Signature nsHttpPipeline::GetConnectionInfo(nsHttpConnectionInfo**) UUID 9be734cd-dcbc-4cb2-8cad-4a0172101203 Time 2010-12-03 15:13:21.958757 Uptime 19508 Install Age 19508 seconds (5.4 hours) since version was first installed. Product Firefox Version 4.0b8pre Build ID 20101203030309 Branch 2.0 OS Windows NT OS Version 5.1.2600 Service Pack 3 CPU x86 CPU Info GenuineIntel family 15 model 2 stepping 9 Crash Reason EXCEPTION_ACCESS_VIOLATION_READ Crash Address 0x0 App Notes AdapterVendorID: 8086, AdapterDeviceID: 2572 MSAFD Irda [IrDA] : 2 : 1 : MSAFD Tcpip [TCP/IP] : 2 : 1 : %SystemRoot%\system32\mswsock.dll MSAFD Tcpip [UDP/IP] : 2 : 2 : %SystemRoot%\system32\mswsock.dll MSAFD Tcpip [RAW/IP] : 2 : 3 : %SystemRoot%\system32\mswsock.dll RSVP UDP Service Provider : 6 : 2 : %SystemRoot%\system32\rsvpsp.dll RSVP TCP Service Provider : 6 : 1 : %SystemRoot%\system32\rsvpsp.dll MSAFD NetBIOS [\Device\NetBT_Tcpip_{77BC9B66-8BB6-4E98-981C-1342464E4270}] SEQPACKET 6 : 2 : 5 : %SystemRoot%\system32\mswsock.dll MSAFD NetBIOS [\Device\NetBT_Tcpip_{77BC9B66-8BB6-4E98-981C-1342464E4270}] DATAGRAM 6 : 2 : 2 : %SystemRoot%\system32\mswsock.dll MSAFD NetBIOS [\Device\NetBT_Tcpip_{BA05DF94-DA75-4230-A3A0-309E80088CFA}] SEQPACKET 0 : 2 : 5 : %SystemRoot%\system32\mswsock.dll MSAFD NetBIOS [\Device\NetBT_Tcpip_{BA05DF94-DA75-4230-A3A0-309E80088CFA}] DATAGRAM 0 : 2 : 2 : %SystemRoot%\system32\mswsock.dll MSAFD NetBIOS [\Device\NetBT_Tcpip_{3D2835C8-1475-4 Frame Module Signature [Expand] Source 0 xul.dll nsHttpPipeline::GetConnectionInfo netwerk/protocol/http/nsHttpPipeline.cpp:231 1 xul.dll nsHttpTransaction::ParseHead netwerk/protocol/http/nsHttpTransaction.cpp:827 2 mozcrt19.dll arena_dalloc obj-firefox/memory/jemalloc/crtsrc/jemalloc.c:4281 3 xul.dll nsHttpPipeline::Close netwerk/protocol/http/nsHttpPipeline.cpp:527 4 xul.dll nsHttpConnection::CloseTransaction netwerk/protocol/http/nsHttpConnection.cpp:648 5 xul.dll nsHttpConnection::OnInputStreamReady netwerk/protocol/http/nsHttpConnection.cpp:1000 6 xul.dll nsSocketInputStream::OnSocketReady netwerk/base/src/nsSocketTransport2.cpp:256 7 xul.dll nsSocketTransport::OnSocketReady netwerk/base/src/nsSocketTransport2.cpp:1526 8 xul.dll nsSocketTransportService::DoPollIteration netwerk/base/src/nsSocketTransportService2.cpp:687 9 xul.dll nsSocketTransportService::OnProcessNextEvent netwerk/base/src/nsSocketTransportService2.cpp:551 10 xul.dll nsThread::ProcessNextEvent xpcom/threads/nsThread.cpp:590 11 xul.dll NS_ProcessPendingEvents_P obj-firefox/xpcom/build/nsThreadUtils.cpp:200 12 xul.dll NS_ProcessNextEvent_P obj-firefox/xpcom/build/nsThreadUtils.cpp:250 13 xul.dll nsSocketTransportService::Run netwerk/base/src/nsSocketTransportService2.cpp:594 14 xul.dll nsThread::ProcessNextEvent xpcom/threads/nsThread.cpp:626 15 xul.dll nsThreadStartupEvent::Run xpcom/threads/nsThread.cpp:207 16 nspr4.dll _PR_NativeRunThread nsprpub/pr/src/threads/combined/pruthr.c:426 17 ntdll.dll _SEH_epilog 18 nspr4.dll pr_root nsprpub/pr/src/md/windows/w95thred.c:122 19 mozcrt19.dll _callthreadstartex obj-firefox/memory/jemalloc/crtsrc/threadex.c:348 20 ntdll.dll _SEH_epilog 21 mozcrt19.dll __dllonexit obj-firefox/memory/jemalloc/crtsrc/onexit.c:276 22 mozcrt19.dll _threadstartex obj-firefox/memory/jemalloc/crtsrc/threadex.c:326 23 kernel32.dll GetCodePageFileInfo The regression range is: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=baa5ae44f0ba&tochange=0ff6d5984287 More reports at: http://crash-stats.mozilla.com/report/list?product=Firefox&query_search=signature&query_type=exact&query=&range_value=4&range_unit=weeks&hang_type=any&process_type=any&plugin_field=&plugin_query_type=&plugin_query=&do_query=1&admin=&signature=nsHttpPipeline%3A%3AGetConnectionInfo%28nsHttpConnectionInfo**%29