Hey Rivet, thanks for your response. I should have remembered that-oldtimers disease is a pain in the @ss!
Oldtimer's disease,

You're not the only one m8, I have my moments too

(edit: Just realized, I might have put my foot in it there. If you are genuinely ill then I apologise) Didn't mean to offend.
Yeah, strange about the choppiness in fullscreen. I don't know the reason either. I haven't quite got film quality smoothness, but it's pretty good.
After my little test all I know is 10 extra frames according to fraps = smoother gameplay. I think I'll leave it in "Windowed" mode.

I don't know about CrossFire, but from what you say, I'd hazard a guess at "no".