I figured out what the problem was and so I'll post the fix in case anybody else is having the same problem and needs help.

I had the ImageZoom add on extension installed, this allows you to zoom images if you want directly on the web page. For some reason it was zooming all images just slightly, so I tried uninstalling it and voila, the pictures aren't zoomed anymore!

As for my computer running slow, I'm guessing maybe that was a separate issue with that spyware that was in my cookies, or maybe I was just over paranoid. Doesn't seem to be slow at all right now.

So as I suspected, it was just an error within FireFox....I guess the recent update didn't flow well with this extension, but I never use that extension anyway. Thanks for trying to help, next time I have a problem I'll have to remember to check to see if my extensions are causing the problem before running all my spyware programs lol