Musescore Window not responding to mouse in Windows 7 - fixed with shutdown and restart

Today Musescore started to behave badly - the mouse click was variable - some things clicked and others did not - almost as if there was a mask over the screen. Alt-key brought up file menu but arrow keys still seemed trapped in the ether - no action. Alt followed by f placed an F on my score in position 1 as if I were in Note mode! Some keys work, but the mouse appears not to be able to press some buttons - like playback - perhaps position has become undefined so playback is at the end, but rewind presses OK but play does not work still and even the playback window shows the same behaviour. I noted also that Windows 7 did not seem to recognize the Musescore window.

after I shut down and restarted my computer, so far the problem of Musescore not behaving has been fixed. It may have been a Windows 7 problem. Musescore did not behave as a window, could not be closed, and could not be dragged or minimized. I have never seen this behaviour before. I have noted in the past that on drag when musescore is on top and a browser (chrome) is behind, that some window lines were left over on the browser. I put this down to a Windows 7 problem. It does depend though on whether Musescore is using special window handling internally. (I am using version 1.1 revision 4611 re-installed a couple of days ago.)