Editing session causes other trees to open

If I'm going through and making a lot of changes to sessions, I'm expanding trees, selecting a session, editing it, then closing the tree. Then I do it again for the next session. However, when I click "OK" in the edit window, it re-expands the trees I had edited sessions in previously. The sessions are usually several levels deep, if that makes any difference. It seems like the symptoms are slightly different depending on whether I collapse all of the subtrees individually or if I just collapse a grandparent tree.