What size screen are you using and what's the resolution set to?
On another forum, even though I have my resolution cranked as high as it will go, the pictures get cut off due to screen size. If I switch to a larger monitor, I get the full picture. Again, this is on a different forum but I believe it's also running SMF (can't tell you for sure since I'm not a mod over there).
I'm using a 15" laptop from work right now and I do have scroll bars that work - Win XP SP3 32 bit and Mozilla Firefox.