Thanks! It's really a great game, (one of my favorites!) 

The upper UI does the same, and is highlighting whatever's behind the "veins of evil" button. I am able to click it and the window that opens works as normal - it doesn't try to select the main screen below it.

I wonder if it's just my computer getting some minor change from some other program.

Thanks again! 
Attachments:
output_log.txt