I recently bought one of those 10-inch AOD257 series laptop for my father.
Two issues with it: Windows 7 Starter and just 1GB of memory. First, upgraded to Win7 Enterprise. After that been thinking to upgrade memory for a while, and decided to try fitting a 4GB stick. Acer suggested it not being possible on their website, but there were some guys on Youtube who did not agree, so I decided to give it a try.

Actually bought this kit for another purpose:

Corsair Vengeance 8GB DDR3 1600MHz SODIMM Kit (2x4GB)

but looked like a nice option to see if it works for this use, just to prove the concept.

Ok, straight to the point - no, it did not work, almost like BIOS never loaded with it. Figured that by the missing screen flash, when the laptop is powered on.
Still it was a good technical experience. If you ever decide to put 2GB in it (that should work, according to manufacturer), be prepared for two difficulties:

• Taking the back cover off (it’s only 5 screws really, but I think had to take almost all of them, since it was not very clear which ones to take out).
• Plugging in the keyboard after it was unplugged. There is a tiny unreliable connector holder there, which did not want to come back in place.

A general advice - be extremely careful when disassembling this whole thing, if it does not go, chances are you missed a screw or a notch.