Well, it may not be the 'dust bunnies', but it is still an overheat problem.
Prove it to yourself... try pulling the side off of your case, and set up a small desk fan blowing cool air directly into the box. See if that helps.
If it does, then you KNOW it's a heat problem, and now it's just a question of 'Which component?'
In all likely-hood, it's your CPU, and possibly just a re-application of Thermal Paste will solve it.
But if your temps are shooting up from 60° to 110°C? then you have a serious problem that you need to fix NOW, before you fry that Athlon 1400
Those old Athlon 1400 CPUs all ran really hot... they consume as much (or more) power as the much newer, and faster, Barton 2800+
Here is my new PCChips M848A' ">http://img.photobucket.com/alb...2_T-2-3-3-6-2_M848.jpg v2.1, with a 1700+ @ 2411 MHz, and my trusty old PCChips M810L' ">http://members.lycos.co.uk/mmm...00MHz_Sandra_tests.jpg v7.1A, with a Barton 2500+ @ over 3500+. Some of my fancy cars are on this pag