I tried to add 256MB PC133 ram and the BIOS said that was fine, so did DOS (from win98 boot disk). WindowsME just shows the splash screen and resets the machine.

So.... I changed it for a PC100 module and that did nothing, BIOS and DOS still have no problem with memory size... its just WinME.

Short of a Win98SE install (which isn't viable) what can I do?

For the curious:
Toshiba 8200 series w/WinME