*** ATTENTION! ***
I've found WHY my GPU was so unstable.
Installing FreeBSD 7.1 I first installed all Xorg + mplayer with XV
It worked FINE with GLX, DRI ENABLED!
When I installed snd_cmi driver (Cmedia sound card) it started to hang
When *NOT* using sound-driver (snd_cmi.ko) ALL is stable, USB keyboard, DRI, GLX, simply ALL, USB2.0 pendrive (EHCI)
When using snd_cmi then EHCI is unstable, DRI, GLX is unstable, ukbd is unstable
that __horrible__ sound driver caused ALL my problems
I have removed sound card (PCI) and all is super-ok
I've tried that trick on 6.2amd64, 6.4i386, 7.1i386, 7.0i386 -> all systems were OK without this card, and NONE was ok with it...
Now using integrated sound on-board VIA (K8TNEO)
I wonder only if driver snd_cmi is corrupt, or my sound-card is damaged??