That's got me beat, since you're the first to post about it that I could see and it worked fine for me.. are you playing in windowed? The only thing that I can think of is if you are then there's a thin strip right around the window border that registers for campera panning.

Not windowed. I tried lower resolutions thinking something similar.

nope, trying to play Random Huge Multi.

On a side note, it will let me pan diagonally down+right only...

Yeah, my thoughts are about the same.  I'm going to re-install and update again first, it's probably just a freak occurance.  I if the problem persists I'll drop them a line.  Thanks to all for the support. Chow.

Good news!