annoying gateway issues

well ive got a gateway select oxn 950mhz tbird comp that ive been trying to installin windows on ive sucessfully install win2000 pr on it but when my family member had for a week she got a bad worm so had to reinstall windows now im gonna put Xp pro and so i added 128mb ram giving her 192mb pc100 but the system doesnt recognize the 128 mb stick i hav to sticks in my inventory 1xpc100 and 1xpc133 and neither is recongnized by the mobo

the ram is good cause it works in one of my computers just fine i know the gateway MSI K7T 6330 version 2.1 worked with the memory cause when i order the memory and tested it, it was tested in that comp but now it does not work the motherboard recognizes the 32mb and 64mb sticks just not the 128mb is this a memory compatibility issues anybody else experience this

Put the 128MB in DIMM 1, the 64MB in DIMM 2 and the 32MB in DIMM 3 and see if that works!