With that stack, it first appeared in 15.0a1/20120517 and occurs on startup. The regression range is: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=c00a9c1940c5&tochange=762e95608da3 Comments say: "gfx.content.azure.enabled true" "Well, crashed with I tried to open my profile, it had gfx.azure.content.enabled to True, so it seems this caused crash." So it's likely a regression from bug 717393. Signature nvwgf2um.dll@0x1c83de More Reports Search UUID 5528208e-639a-439d-bfcb-db54d2120517 Date Processed 2012-05-17 19:55:46 Uptime 2 Last Crash 2.5 minutes before submission Install Age 3.9 hours since version was first installed. Install Time 2012-05-17 15:37:51 Product Firefox Version 15.0a1 Build ID 20120517030523 Release Channel nightly OS Windows NT OS Version 6.1.7601 Service Pack 1 Build Architecture x86 Build Architecture Info GenuineIntel family 6 model 26 stepping 5 Crash Reason EXCEPTION_ACCESS_VIOLATION_READ Crash Address 0x8 App Notes AdapterVendorID: 0x10de, AdapterDeviceID: 0x0e22, AdapterSubsysID: 216619da, AdapterDriverVersion: 8.17.13.124 D2D? D2D+ DWrite? DWrite+ D3D10 Layers? D3D10 Layers+ EMCheckCompatibility False Total Virtual Memory 4294836224 Available Virtual Memory 3850285056 System Memory Use Percentage 35 Available Page File 9219969024 Available Physical Memory 4137152512 Frame Module Signature Source 0 nvwgf2um.dll nvwgf2um.dll@0x1c83de 1 nvwgf2um.dll nvwgf2um.dll@0x61efa 2 nvwgf2um.dll nvwgf2um.dll@0x5154d 3 d3d10_1core.dll NMultithread::CDevice::Draw 4 gkmedias.dll mozilla::gfx::DrawTargetD2D::FillGlyphsManual gfx/2d/DrawTargetD2D.cpp:1922 5 gkmedias.dll mozilla::gfx::DrawTargetD2D::FillGlyphs gfx/2d/DrawTargetD2D.cpp:898 6 xul.dll GlyphBufferAzure::Flush gfx/thebes/gfxFont.cpp:1593 7 xul.dll gfxFont::Draw gfx/thebes/gfxFont.cpp:1985 8 xul.dll gfxTextRun::Draw gfx/thebes/gfxFont.cpp:4751 9 xul.dll nsTextFrame::DrawTextRun layout/generic/nsTextFrameThebes.cpp:5624 10 xul.dll nsTextFrame::DrawText layout/generic/nsTextFrameThebes.cpp:5756 11 xul.dll nsTextFrame::PaintText layout/generic/nsTextFrameThebes.cpp:5612 12 xul.dll nsDisplayText::Paint layout/generic/nsTextFrameThebes.cpp:4448 13 xul.dll mozilla::FrameLayerBuilder::DrawThebesLayer layout/base/FrameLayerBuilder.cpp:2554 14 xul.dll mozilla::layers::ThebesLayerD3D10::DrawRegion gfx/layers/d3d10/ThebesLayerD3D10.cpp:492 15 gkmedias.dll mozilla::gfx::Factory::CreateDrawTargetForD3D10Texture gfx/2d/Factory.cpp:331 16 xul.dll mozilla::layers::ThebesLayerD3D10::Validate gfx/layers/d3d10/ThebesLayerD3D10.cpp:286 17 xul.dll mozilla::layers::ContainerLayerD3D10::Validate gfx/layers/d3d10/ContainerLayerD3D10.cpp:388 18 xul.dll mozilla::layers::LayerManagerD3D10::Render gfx/layers/d3d10/LayerManagerD3D10.cpp:686 19 xul.dll mozilla::layers::LayerManagerD3D10::EndTransaction gfx/layers/d3d10/LayerManagerD3D10.cpp:355 20 xul.dll xul.dll@0x1325cf 21 xul.dll nsDisplayList::PaintForFrame layout/base/nsDisplayList.cpp:679 More reports at: https://crash-stats.mozilla.com/query/query?product=Firefox&version=Firefox%3A15.0a1&range_value=1&range_unit=weeks&query_search=signature&query_type=contains&query=nvwgf2um.dll&do_query=1

This should be fixed in today's nightly. See follow-up pushed in bug 717393

Based on comment 1 and crash stats (happens only in 15.0a1/20120517030523), I close it as fixed