Inspiron Duo memory upgrade?

in the setup-guide at specifications the memory-size is said to be limited to 2gb. is that true?

I've seen people on the net write they upgraded their memory on inspiron duo, and it is quite unbelieveable a 64bit processor couldn't take more. also searching for inspiron1090 showed a 4gb module, on the dell-site. also strange that max and min size of memory is the same. as far as I know the module-size is limited by how much energy the system can provide and how much heat it can take, so I suspect that with newer technology that maximum amount of memory could be increased if there would be info on why the memory is limited...

I'm asking because windows keeps on crashing, especially problems with display are frequent, simply because of windows7 using up vast amounts of memory on its own and leaving only little to other programs. somehow I doubt this is the right operating-system for this computer, unless I can get more memory into it. or should I downgrade to an older, less memory-hungry windows version? but then, I'm afraid there are no drivers...