Are they different sticks? Some are not compatible to run with other makes. With RAM you should really run the same make stick in each slot.

Originally Posted by allcart

Slot A0....512MB
Slot A1....256MB
Slot A2....256MB SDRAM DIMM
Slot A3....Unpopulated

If you've got DDR2100 how come slot A2 is showing SDRAM I dont think you can run DDR and SDRAM at the same time try removing the SDRAM and see how that goes..

Thats what is confusing me.
I have only got 2 chips. Both DDR.
I have run loads of diagnostic proggies and keep getting conflicting info.
I have removed and reinserted both chips..... At this time,
slot 1....512MB DDR
slot 2 ...256MB DDR

Sys info says:
total memory 512MB
available memory 524.79MB

On bootup it counts 768432K

I am stumped

But are they different makes of stick?

Originally Posted by HappyBeaver

But are they different makes of stick?

Err, yes.
Could that be the root of my problem then.
Looks like i'll have to buy another stick then.

I'd say that was definately the answer. For example, if you tried each stick independently, and they both registered with the full quota you know the sticks are ok. The only two possible problems are incompatible sticks or dodgy slots, which I very much doubt.

Buy a new 512 stick of the latest and greatest and sell what you have

Ok thanks for the advice.
And thanks to everyone else who tried to help.
Its much appreciated.