I've noticed this before, and now it's happening with a custom tool kit I've been developing.
I have a simple Custom PPG defined in a self installing plugin and am applying it to multiple objects in the scene. However, if I multi-select the objects, the PPG doesn't show up at the top of the selection explorer. If I open the PPG on one of the objects, then multi select other objects with the same custom property, the title bar of the PPG reads "[multi]", but none of the multi selection features work... if I edit a parameter, it only affects the first item in the selection. What gives? Is there a way to construct the PPG in order to avoid this behavior? I really need them to work in multi-selection mode! -B