Powerbook Rattling

Hey guys, I have a new Powerbook, I have put some extra ram in it, so now its 1.5, 1gig, I have the 80gig 5400. Everything was cool for months but now if I run too many apps, or it looks like there is too much strain, I hear this pretty loud rattling. Anyone have any experience with that? Or heard of it?

It sounds like it is coming from the center/back left

It's probably just the fan..
Maybe there is something between the blades, or some dust is stuck around the bearing?

Or is it just the normal fan sound?

No its not the fan, at least I don't think it is, as it just started happening within the last month (and I have had this for 4 or so).
If it is the fan, what can I do about it? Do I have to send it away? or should I open it up?

If you have an Apple store near by, take to them and have them take a listen.

Yeah guess I will, it happens almost ALL the time when I use Virtual PC (I know I shouldn't but I have to play my Poker Stars).

I'll let you konw how I make out...