http://bugs.winehq.org/show_bug.cgi?id=11944
--- Comment #1 from Roderick Colenbrander thunderbird2k@gmx.net 2008-03-09 05:53:17 --- The first thing to do would be to run with: WINEDEBUG=+wgl,+x11drv,+synchronous wine steam.exe &> log. (Hopefully it is the steam binary itself as else you would have to explicitly set WINEDEBUG, so that all apps see it)
Most likely winedbg will be launched after the crash, attach the 'backtrace' log it shows, so we can see where in the code it crashes.