Performance hit under Vista ... solved!
Some customers reported the following problem under Windows Vista: when positionning the mouse over the PropertyGrid, the cpu was raising at 100% and as a consequence the grid was experiencing redrawing problems when expanding nodes, checking radiobuttons, etc. I worked this week on this issue and discovered the culprit: VisualTips.
This wonderful component from Skybound was indirectly sending a ton of MouseMove events to the grid (and to any control on the form). The cause of this behaviour has not been found precisely but the people there fixed the bug related to another 100% cpu symptom. If you are using VisualTips and your product also targets Windows Vista, you have to get their update.