Maximum RAM Size for SONY VAIO Laptop PCG-F series

Recommended by Wim's BIOS...

I have a problem with my Sony laptop PCG-F403 (bought in UK) but about the same as F430 (USA) ... Manual says max 256mb RAM (2x 128mb) but since its publication there has been 256mb modules and 512mb modules in those 144pin PC100 SOSIMM SDRAM type that physically fits the slots.. Sooooooo ... does any one know if this laptop will take these higher rams? I really want to put in a total of 512mb (2 x 256mb) because the present 192mb (original 1 x 64mb PLUS 1 x 128mb I added already some time back) is not enough for my XP and programs. And does anyone know what controls how much MAX memory can be fitted? Is it the BIOS? If so, does the new BIOS (that troublesome one), see more than the originally stated 256mb? Or is it something else that cant be changed that controls the MAX Memory? Is there someone out there that knows the answer to my problem? Or who has put the 2 x 256mb in one of the PCG-F series and got it working?

[edwin]

nope 2x 128MB is the limit. Nothing can be done about that, although the newer modules fit physically, the chipset cannot address all of the memory modules. So if they work at all the max size they'd show would still be 128MB per module...