I have just installed RHL 6.1 on a totally separate HD from windows. The install went smoothly, but when I first booted up the system, my keyboard stopped working at the login prompt. I couldn't turn capslock, etc. on or off, I couldn't ctrl-alt-delete or anything...but the cursor was still blinking under login, so the OS didn't freeze. The second time I booted up I managed to log in successfully, but then the same thing happened 30 seconds after login in the middle of xconfigurator. I've tried three other times with similar results, and it looks like my mouse get screwed up as well. I have ps/2 mouse and keyboard ports, and everything works fine in windows. I couldn't find an acceptable component for this bug, so I selected console tools. If this is the wrong area, please tell me and I will repost it to the correct place.
you are definitely experiencing hard lockups. The cursor doesn't freeze because it is run by either your video card or bios, which may not lock up even if the rest of the computer does. Chances are you have flakey memory if you are experiencing these random intermittent failures.