Main window freezes with brief playback

[heinzfan]

Occasionally, randomly, when I click the "play" tool button and then stop after 1-3 measures the main window will no longer respond to the mouse. The scroll bars will not move, the tools will not work. Items in the main menu can be selected, the file can be saved, but any menu items that use handles in the main window will not respond. For example, speedy doesn't open the editing frame; expression tool will not work, and a visible handle can't be clicked to open. I've tried every means I could think of to "unfreeze" the window: all notes off, redraw, change tools, views, go to a different measure, play, but the only thing that works is closing the document and then reopening. I don't see any spike in memory or ram. I'm using Vienna VSTs, not Garritan, perhaps some type of lockup between the VST player and Finale? It's an annoyance, not critical, since the document can be saved, but has anyone else experienced this problem?