play controls stopped working

[jeffdanner]

Hi,
Is there a switch that would cause all the controls (play, stop, pause, record, etc) at the lower left of the multitrack view to not function? They did function, and now they don't. Neither will the track play by hitting the space bar.
The rest of the program - the menus in multitrack and everything in the edit view - still work fine (including play, etc).
I'm talking CEP 2.1, of course.