The tree component using AJAX method is broken in IE7. Easily reproducible.
Go to the RichFaces demo site, check out the tree component. Locate the AJAX-style tree, and repeatedly expand/collapse quickly an arbitrary set of nodes in IE7. A javascript error should appear on the bottom left corner with the error message: Tree.item.findComponent(...) is null or not an object. This problem does not exist in Firefox.
Are there any plans to fix this?