Steam crash on exit

[eAi]

I got this crash when quitting steam:

Call stack snipped:

0 vgui2_s.dylib 0x173de2f2 CVGui::PanelToHandle(unsigned int) + 34
1 vgui2_s.dylib 0x173e00d2 CVGui::PostMessage(unsigned int, KeyValues*, unsigned int, float) + 82
2 vgui2_s.dylib 0x173d1eb3 -[VGUIApplicationDelegate applicationShouldTerminate:] + 227
3 com.apple.AppKit 0x909dcd5a -[NSApplication _docController:shouldTerminate:] + 84

Full log:

http://pastebin.com/6hQ1XyKd

Apologies if it's know or this isn't the correct place to report it!