XnView Software

Hi all!

Sudden problem happened overnight. Today out of the blue I realized I cannot cause an image to go full screen when I click the center mouse wheel. It always used to do this. Now nothing happens. Can anyone tell me why, or where the setting is for that? I've checked everything and cannot figure it out. Thanks!

Oh boy. It just got weirder. Now when I click the mouse wheel, it goes full screen, but with a gray border around it and the top menu bar showing. If I click the mouse wheel again, it goes full screen like normal. Then back to the gray border. But I can't get out of full screen mode. What's going on?