Choppy Synchronized Scrolling in FireFox

I have a strange problem with firefox 5.0. I have two div's with a fixed size and content. Div A has set the overflow property to hidden and div B to auto. The scroll Event of B is called and in the callback function the scrollTop and scrollLeft values of A and B are synchronized. In Chrome and IE everything is fine, but in firefox scrolling is choppy. I found out that the scrollTop and scrollLeft value in firefox do not increment or decrement fluently like in Chrome and IE. The values of scrollTop/Left are jumping when I am scrolling fast. I tested all this on my Notebook with an external USB mouse. The stran开发者_C百科ge thing is that if i do the same with the touchpad of my notebook scrolling works just fine in Firefox.