http://www.computeranimal.com/memory/8305.html
(you have 2 dimms right?)
this is what makes me think it only supports 256MB, no one sells 256MB chips and if you only have 2 dimms, youd have to have 256MB chips, but
www.computeranimal.com is saying 256MB chips are not compatible
i hope this clears things up a bit, and im sorry there aint anthying else i can reccomend doing, unless oyu have a friend with a couple of pc100 sticks of 256MB, and you could just try em? i mean, that woint hurt anything, so its worth a shot (i wouldnt go buy em and try and return em, whatever you do) the only other thing i could think of would be to replace your mobo