hmmm. I have no Idea whats causing that... I don't know if this makes any sense but when I leave my computer on for days on end F@H seems to slow down, so I restart, then its fine... It might be me just thinking it works.
Got this of a site....
"There are other advantages to turning off your computer a few times per week. Keep in mind that every time you restart your PC, your operating system flushes out older files that it's not currently using. Not only does this reduce file clutter on your hard drive and in RAM, it may even provide noticeable performance boosts."
I know F@H puts somewhat large demands on RAM
It might be me just being a tard but it seems to work for me...
How long have you had your PC on???