Shut Down Difficulties

I've got an Intel D850EMV2, a P4 2.26Ghz 533 FSB, and 256MB RDRAM PC1066 with SuSE 8.0 installed on a second drive. Installation went flawlessly, but when I try to shut down, SuSE 8.0 goes through all its paces to reach run level 0 but does not turn off the machine! I've gotten exactly the same result entering either halt or halt -p from the command line in single user mode. Why is SuSE 8.0 not shutting off my machine, can anyone tell me? John Lowell