Catching the strum pattern is rather tricky, they almost never indicate this on tabs and what not. U tend to get the hang of it after a while as u learn more songs and try to improvise. Im sure everybodys telling u the samething so lets see if we can fix that.
Mind you, im trying to work this out from memory (in the office at the moment

), and the timing might be a lil different... I'm going for the chorus part of the song "If i could, then i would..." Lets say:
D= down stroke
U= upstroke
Dx or Ux = mute and stroke down or up respectively
So "If I could.." would be sumthing like this: D Dx U Dx U Dx U
This part repeats itself through out the chorus. U need to get the timing down. I think the best solution is to YouTube it and see la, easier to see how it flows.
By now the guys in the office are giving me weird looks playing air guitar in my cube