Bug 4365758 is marked as integrated in Merlin, but mouse wheel scrolling still isn't correct for JTree. This is easily reproducible using the Tree demo of SwingSet2. There are a couple problems:

* By default, one click/rotation of the mouse wheel should scroll by three nodes, and shouldn't ever scroll so that a node is partially visible. When repeatedly mouse scrolling down (or up) an expanded JTree, scrolling is often done by an incorrect amount.

* Mouse wheel scrolling down by one "click", and then up by one "click" should leave you exactly where you started, but it doesn't. Starting from the top of the Tree demo, it takes _6_ iterations of wheel-down/wheel-up to get back to the very top of the tree, each wheel movement leaving you in a slightly different spot.

Correct wheel scrolling can be seen in the Table Demo, the List Demo (though not in the Prefixes and Suffixes boxes), and the ComboBox Demo.