I'm sorry, I don't speak English very well.

I use linux since six years without problems.
Recently, I have updated Xorg to 6.8.2 version (Slackware package)
because old Xorg versions are very unstable; after that upgrade, I have
noticed X random crashes during execution of whatever fullscreen program
(like xscreensaver, KDE screensaver, tuxracer, etc).
Sometimes the crash comes after a few minutes; sometimes after many
Xorg totally freezes (keyboard doesn't respond) and I must reboot.
The crash disappears only when DRI is disabled (but, obviously, I don't
want to use Linux without DRI).

My graphics card is a 3Dfx Voodoo3 3500 TV AGP (AGP to PCI Bridge AMD
Irongate 751); this card is perfectly supported by Linux (Quake III
Arena runs at a framerate greather than Windows).

In the kernel (2.6.12) I have enabled MTRR, agpgart, amd_k7_agp, dri
and framebuffer support for voodoo3/banshee; the crash also happens
with mtrr or amd_k7_agp or framebuffer disabled. Glide3 libs and Glide3
SDK are correctly installed (Slackware packages).

In the Xorg BugList I have noticed that many users have reported same
problems with Ati cards and nVidia cards!

Anyone can help me? I'm very desperated!