from his post, i can tell that it was a cooling problem. Dust is a very bad thing. It can get in the fan motors and burn them out. The one thing i have on my PC is fan filters. I clean them out every so often. When i do clean them out... THERE LOADED With dust. I also have a bird in my room so maybe thats y. I also have 2 cats that spend some time in here too sleeping ect.. But people say that they slow down the air flow. They may slow it down like 1 or 2 CFM but thats it. If you get the good kind then you will may not even notice a difference... But make sure u keep it clean. What i do is every 3 or so months, i take my computer and i just clean all of it out. meaning i take Endust for electronics, (best stuff for PC's) and i clean the outside, inside and everything around it. Its the best thing. But since u did all that cleaning, it seems fine. If it happens again with no dust, then u have a cooling problem.