Thanks for the response jaywoo. Sounds like you are correct with the speed mismatch thing. The seller sent me wrong RAM modules as the ones supplied to me are PC2-5300S modules. For your info they have 8 chips on either side, but as they are wrong anyway, no need to progress any further. Cheers again for the help, I wouldn't have known otherwise, and been scratching my head for the next few weeks wondering what the problem is.
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