Harry
Well, as I posted, I wasn't supprised by the phenomena.. and stated my specs were too low. The surprise was in the fact both win2k and winxp can do considerably better on that machine. At least in terms of laoding the gui and running gui tools.
Sorry if I've missed a crucial part of the background to this problem, but...
Check if you're running any daemons or services that are not available on other OSs. I turn off sendmail, cups, anything else I don't use.
Also make sure the other OS is providing the same level of features, so you're comparing like with like. I have an ancient Win95 machine and it runs old apps acceptably, but struggles a bit with modern ones. I stopped dual booting it after I saw how slow FC1 was on it.
-Cam