At least on de_dust/de_dust2 and "dust-based" maps (e.g. de_dust2_unlimited) after map change or reconnect to server with sv_pure 1/2 (all materials & models from trusted_source, except vgui/thumbnails) I see this:

Also, very often game crashes after this.
I'm running Win 7 x64, but many friends and players reports me about this problem (They use Win 7 x64/x86, Win XP x86), and I see that after mapchange online falling from 40-50 to 10-15 players, because of crashes I think. So I think that this problem not related to hardware and/or OS.
Prerelease beta not fixed that, I have one server on beta and one on release versions, changed my client version, but this bug is still here.
PS: Server is on Linux, this bug happens even without MetaMod/SourceMod