I'm running XFree86 v4.01 (rh 7.0). After hopping out of X into a virtual terminal (using alt-ctrl-FunctionKey) X will usually crash within a few minutes. It will die with a standard segfault error and then a bunch of GTK messages angry because X has gone away. I'm running a stock Rh7.0 install with gnome. My box is a dual PIII-450 with a VooDoo III PCI card. I've tried using the expirimental dri driver with the same results. X seems to run fine if I don't switch to a VT. please let me know if you need any more info. I couldn't find a core file from XFree86, but if you need one just let me know what to do. Thanks.
What video mode and color depth are you using, and do you have DRI enabled? Attach your X server logs and config file using the link below. If you are using DRI, you must use 16bpp color depth as other color depths are not supported I don't believe. You might also want to give the latest Rawhide version a shot. XFree86-4.0.3-5
Fixed in 4.0.3-14 in rawhide