Hi again.
I've tried a couple of things since last, and it seem it has had some effect.
I started out by opening the case and removing my MP3- and DVD-Drive.
Turns out the MP3 HD (250gb Maxtor) wasn't an IDE-drive, but a SATA as well. I'm not sure which version though..probably SATA1.
After that, i made sure my 2 remaining drives were connected to the Intel Chipset. They are now connected to SATA2_1 and SATA2_3 on the mobo.
I also found a tool that removes all things ATI related (amd_cleanup_util_1.2.1.0).
I then installed the lastest drivers for my card.
I also set my Page file to 100-100 on my System Drive, and 4096-4096 on both partitions on my secondary drive.
I ran Latmon again running the same game as before:
(Note that the screens in my first post was at 13mins, while the new ones were only 6 mins.)

@Deek
Thanks for joining
No, i haven't run chkdsk, defrag or malwarebytes yet. I'll do that next.