memory reading problem plz help :)

[InCredible]

i have a gateway laptop with a single dimm..i installed a 1gb stick which is the max that can be installed in this laptop..however for some odd reason the OS is only reporting 512(496mb after 16mb for video) ...cpuz reads that 1024mb is installed in the laptop..so can anyone shed some light on to whats the problem?

the OS in windows 7..its a single 1gb stick of compatible memory..theres only 1 dimm(no hidden dimms under the keyboard etc)
its an mx3225 if u need any more specs

any help would be greatly appreciated..thanks

[InCredible]

nothing?

[BenchZowner]

Sounds like a compatibility issue or a problematic SO-DIMM slot or memory controller.
I'd try another DIMM.

[InCredible]

thats the problem with the laptop..it has only one dimm... and cpuz shows that 1gb is installed but the OS only shows 512mb