http://bugs.winehq.org/show_bug.cgi?id=19659
--- Comment #30 from Stefan Dösinger stefandoesinger@gmx.at 2010-03-10 03:04:43 --- I fixed a crash added by some buffer changes a long time ago(that was maybe around 1.18) where the buffer code called GL without acquiring a context. Maybe that's why the crash is different in .39(different bug) and why there is no context_acquire call.
A while ago context_acquire was called ActivateContext and didn't return a context pointer. I don't remember when this was changed exactly.