Problems mousewheel scroll speed across browsers


Now I develope a new theme, but I have a problem . This problem I found at the others themes from here .

On Safari or Firefox my page have a nice scroll but on Chrome or Opera it sucks compared to Safari, Mozilla. On these browsers has a small lag and speed is not constant. After much searching I found this :
and this :

But it does not solve the problem. Does anyone have a solution?
I use Mac, I have not yet tested on Windows .