This problem has existed with both Firefox 13 and 14. Two finger scrolling works briefly, then stalls. Clicking above or below the scrollbar button doesn't work, nor does using the scroll arrows after the stall occurs--only grabbing the scrollbar button and dragging it works. After doing this, two finger scrolling works again briefly before the problem recurs. This on my 17" Macbook Pro running OS 10.6.8.

hey natchilds, try to switch off smooth scrolling in preferences > advanced > general

All right! That did it! Thanks, madperson! Much appreciated!

I had this problem on my MacBook running 10.6.8, and fixed it with the suggestion to turn off smooth scrolling from madperson.

I just moved to 13.0.1 and smooth scrolling is now the default, which screwed it up again. :(

Since smooth scrolling automatically messes up scrolling on these machines, perhaps having it as the default is a poor choice.

I'd suggest either going back to NOT having smooth scrolling as the default - or fix the problem, folks. :)