Look at the sidebar.xul file and begin selecting items in the tree view (by single clicking on the items). Old items are not deselected when new items are selected, despite the fact that the attribute selector rule no longer applies. If you mouse over the old items (the items that should no longer be selected), they redraw correctly, and the selection disappears.

assigning incremental reflow and collapsing border bugs to buster

This is a bug in the XUL content model. It's fixed.

Steve: Using the 3/26 build on Win 95, Win NT, Win 98, Mac8.5 and Linux, bug is fixed in terms of selecting/deselecting. However, there is some buggy behavior on Mac when you select items. On other platforms, when I click once, one category is deselected and one category is selected. I have to double-click to open up the category. Quirky behavior on Mac: (1) Sometimes a single click opens the category and cometimes a double-click opens it (not consistent) (2) When the category is opened, the previous category gets highlighted. This doesn't happen if I am double-clicking to open the category. It only happens when I single click and the category opens. Is this a new bug or part of the same problem? Please advise.

This sounds like a bug in click handling in the tree widget, not a generic problem with tables. I'm reassigning to David, and if his investigation points back at tables then I'll look into it.

It sounds like the original bug described here is fixed. Heck, the new problem is on Mac only, and this bug is PC/Other. If so, this report should be closed. Any subsequent defect should be described in its own bug report, so we can track them and test for regressions separately. ChrisD, could you please open a new bug report with your comments?

Marking bug as fixed for original problem. Opened new bug #4507 for quirky Mac behavior.