It's a total system freeze, cntl-alt-backspace doesn't work. Even telnet sessions into the box to try to diagnose the problem stop responding.
I should also mention the 1.03 bios system reported a Grub error 28 ("Selected item does not fit into memory") where the 1.001E system did not, grub worked fine on that system. (I used dd to extract the first 512 bytes of the Linux /boot drive and used the NTloader to load linux by linking to the extracted file which I placed on the Windows drive and adding a line to the boot.ini file under Win2k.) I've seen this issue mentioned on this forum elsewhere.