yep, check /var/log/messagesCan someone please tell me which log files should I check to find out what is happening.
Why do you keep reinstalling when something crashes? Try just rebooting next time, and when you get in, run on the commandline 'up2date -u'. Make sure you go to www.redhat.com to register your setup :P
Beyond that, maybe you should try doing a disk surface scan to check for bad sectors.
Let me know if this helps