You were having issues with FF on the Apple PC not the Windows PC? What about using Safari on the Apple PC and the Windows PC, do they both work? What about Opera and Chrome?
Hey, a reboot is the obvious cliche that can sometimes work.
Works for my Windows PC when it has been processing heaps for 3 weeks straight then give it a reboot - it runs faster. Also the Apple PC at work had to do a reboot after 1 week running - the Graphics dude was nervous as he knew I knew what was going on and tried to not talk about how his Mac crashed.
I wouldn't have taken the piss out of him, even though I could have.
I should have taken the piss out of them when they had no idea about that button battery on the MB though! I did mention it like I said the other day, but they looked blankly at me and ignored me - typical Apple users at my work - clueless with technology... Then when the 'Apple specialist' dropped by he said exactly what I said and they didn't even acknowledge that I said that earlier... iDiots.
Apple PCs Windows PCs Ubuntu PCs the guts of how they all run are the same, so easy to work out what a possible issue is.
These iDiots at work have no-clue about how their cars and computers work! The one Windows PC at work is a prime example: It has an inferior 4:3 monitor that is using an old connection that leaves trace 'ghosts' on screen. This PC runs the 2 digital printers that print directly onto the tee shirt. The Apple PCs can not run these printers. The Windows PC can. Its mouse refresh rate is so-sloooow!!! Pisses me off heaps! I did reset the monitor and mouse settings plus a few 'tweaks' on the desktop to make it a better computer but had to dumb it back down for the Apple boss who'd be 'lost' if anything were altered for the better... Still needs a better monitor for some post-editing is used on it for resizing and altering hue on prints using PS CS.