Lightroom Panels Disappear - NOT a "Tab" Key Issue

This really weird and has been going on for weeks...when Lightroom has been minimized and I go to activate it, the area where the panels should be are either dark or they're missing.  If I quit Lightroom, I notice that when the message about backing up my catalog appears, the middle screen disappears, but all the panels are suddenly there -- as if they were hiding BEHIND Lightroom before they, too, disappear.  It's as if I was running two separate programs.  When I restart, everything is hunky dory -- until the next time I minimize it.  Quit, restart, repeat.  When I called Adobe, the tech eventually reset my Lightroom preferences and called it a day because when it restarted, all the panels were there.   I've optimized my Lightroom catalog but that didn't change anything either.  But the situation continues to occur.  Any other ideas out there as to what may be going on and/or how to fix it?