I just got it back from Dell this morning, the paper says "The actual fault found by our technicians: faulty motherboard - fan" and "We have replaced the following items: motherboard - fan". So it looks like our speculations were pretty accurate.
I'm running it now and it seems to work fine. I'm installing a few games to really test it but right now the CPU temperature is at a steady 36 degrees C. I was a bit annoyed that they didn't mention the fact that I never got a Windows or Drivers and Utilities CD with the notebook when I got it, and even though I wrote a note detailing my issues with the computer they never addressed the issues of the missing CD.
I understand that the drivers are all available online, but in this case the native WinXP ethernet drivers don't work with Dell's card, so I couldn't get online to download the drivers. The notebook came with WinXP installed - I didn't want it installed, but still, I paid for the software, shouldn't I have a copy of it? I may have misread the small print, maybe the OS only comes installed and not on a CD, so I'll look into it more before I decide if I want to complain.
So it seems to be working just fine now, I'm glad
