Found the culprit of hangs with timedemos (at least in my non released beta
):
In fact happens in game -just use crusader with "sunstaff" weapon for example or when a wizard attacks you : possible crash in game or most likely when closing game-.
Particles.
Load game with the minimum "-particles 512". The maxparticles used by default ( a wooping 7000) exceed minigl vertexbuffers.
Hope this bug ends for the time being. Or wait for new bugs in the next build.