Hi. Thanks all for the replies. I just tried to re-install Maya, but the problem still persists.
It's a fresh installation, so it's not because I somehow screwed up the configuration of Maya.
My RAM is, as far as I know, perfectly fine. All other applications on my machine work fine.
I'm starting to suspect it's some kind of the incompatibity of Maya with my VideoCard.
As I've mentioned in the previous post, my video-card is a low-end one that came with my PC (HP Pavilion), called S3 Graphics ProSavage. As I've checked the AliasWavefront's website, my card is not supported by Maya. Would that be a problem?