Sony :: VGN-C1Z (Intel 945PM) With More Than 2GB Of Memory

I just bought 2x2GB (DDR2 667MHz) of memory for my VGN-C1Z laptop (unfortunately I did not check before if 2X2GB was supported). Now, as far as I understood the Intel 945PM should support this, but the laptop in itself was said to be 2GB limited.

Using Windows XPPsp3 with those 2X2GB success to boot but at the end I got black screen (I see the Windows logo and progression bar, it stops displaying some sec before the startup sound), then I success to remotely connect to the laptop through VNC, here I can see that Windows is reporting 3GB which looks "normal", and under driver tab I can see in system area a warning under the line "Mobile Interl(R) 945GM/PM/GMS/940GML and Intel 945GT Express PCI Express Root Port - 27A1" saying "This device cannot find enough free ressource to work properly (Code 12). If you want to use it you need to unactivate one of the other system device" [message was in French, this is my translation], the version of the pilote is 7.1.0.1015. I'm using BIOS version R0035J4, in the BIOS only 3GB are reported. Running Everest I saw that PAE is supported and activated, and the memory is detected, you can see here the Everest report: [url]

If I boot with 1x2GB it's ok (so the mem slot works ok against 2GB). If I boot with 1x2GB + 1x512Mo, it's ok too, so It's above the 2GB limit announced.

I tried to change the video driver, and also switch to VGA with same black screen of course.

So... what can I do next to try to have 2x2GB working (even if only 3GB are available) ? Does it looks a driver/Windows issue ?