Slow Grid with relatively small dataset

I have a grid of 40 rows and 13 columns, and it seems to move really slow. What could be causing this?

Adam,

could you provide any details?

http://www.activewidgets.com/javascript.forum.13117.6/performance.html

What 'exactly' is slow - loading, repaint, scrolling, selections?
How much compared to standard examples?
On one machine or on many different ones?
IE or Firefox?
Can you measure it?
etc.

Actually, the scrolling, selections, and mouseovers seem to be delayed. I am testing on both IE and Firefox, and I have two machines that I test on. It also seems to bog down the page cause buttons click are delayed too. I didn't have this problem when I split the grid into 3 different grids.