I have seen one other case with this behavior but I doubt it is causing your problem.
I frequently use "select with constraints" to determine if I have n-gons, non-planar, non-manifold geometry.
I just as frequently forget to uncheck the thing I am trying to select for then invariably scratch my head for 15 minutes before I realize I have select only non-planar or something checked and maya refuses to select anything.
But as you are clearly leaving and restarting maya any select with constraint options would be reset.
I am still thinking about it though and if anything comes to mind I will post it.
Have you changed any hardware, gfx drivers, gfx cards, in particular? I hate to fall back to the old "Have you reinstalled maya?" recommendation but...
"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675
Last edited by ctbram; 03-01-2010 at 07:06 PM.