I tried both LG drivers for the graphics card and the oficial ATI catalyst drivers (which had to be installed with the help of the Mobility Modder), but none worked for me.

In the meantime I was able to figure out what is preventing Vista to allocate the needed resources for the graphics card to work: I recently installed 4GB of RAM (2x2048) which replaced the 1GB that I used to have on my laptop (2x512MB). For some reason Vista doesn't seem to be able to handle this configuration, whereas XP is able to do it.

I know that using 4GB with a 32bit operating system will always result in less RAM used than what actually exists, but if XP can handle the 4GB, why isn't Vista doing it?

BTW, my laptop chipset is the Intel 945PM Express.