Re: I've got a bit of a soft spot..
I think that the AOA 532h takes DDR2 and your CF-53 is DDR3?
I just use the best value for money that Ebuyer sell, faster speed ram is fine and is often cheaper as it's more "current".
I've got 4GB sticks in all of my netbooks and am working on bios mods to allow a 64bit OS on the HP minis.
All good fun!