Eventually done this. Ran the system scanner on Crucial web site and the Laptop can take any of the following (so if you have any spare please holler hehe)
1Gb DDR PC3200, CL3, Unbuffered, NON ECC, DDR400, 2.5v
1Gb DDR PC2700, CL2.5, Unbuffered, NON ECC, DDR333, 2.5v
512Mb DDR PC3200, CL3, Unbuffered, NON ECC, DDR400, 2.5v
512Mb DDR PC2700, CL2.5, Unbuffered, NON ECC, DDR333, 2.5v
Cheers all
John