This is an old project developed before the first release of jQuery. Now I think the only useful component is the tree, so I clean it up and create a new project for the tree only

Style One Style Two
the nodes your want to load:

We may doubt if we need to load a tree with more than 200 nodes,and let user to select from one of them in the UI?I think it is a bad smell.
I use this in many project,and have test it many many times. I think it useful to share these experience.
The biggest check point is the image,do not handle the image filter by youself,and let the container do it.On a dynamic web site,the IE can load 2000 nodes in one-time mode and 7000 totally in lazy-loading mode.Firefox is work well when loading 8000+,I didn't test anymore.
As this test is a static local environment,I show the result here I have Test:
nodes number IE8 Chrome3.0 Firefox3.5
1000 2687(ms) 514(ms) 2026(ms)
10000 134954 6495 42416