Fedora Hardware :: Experiencing A High Degree Of Hard Drive Access

I'm using my F11 box primarily for browsing. And I have freakishly low RAM (256). All was good up until recently. Now Im experiencing a lot of HD access with a lot of grinding and HD light flashing at different intervals when going online. I've searched but found no mention of viruses that would do this. I would typically associate this with a lot of downloading, as with software update. However I've disabled this program (since the box was in a stable state for my intended purpose and I did not want to invite new maintenance).

Any ideas what could cause this? It can become so intensive that the mouse is practically disabled and any attempts to close a window take upwards of 15 minutes. I frequently receive the Firefox message that the application has become unresponsive, do I wish to kill the program or wait.