The apitrace-related crash from those earlier comments is not an XCOM bug.
However, if I recall correctly, XCOM issues DrawRangeElements calls with ranges
that are larger than necessary. This hurts performance slightly when vertex
data is not in VBOs; it is irrelevant when all vertex data is in VBOs.

I have been able to reproduce the lockup (thanks to Edwin), but it takes a
fairly long time inside the game to happen for me. With everything else that is
going on, I simple haven't yet had the time to collect enough information to
really understand what's going on.