Window I'm using deselects

[Ja Di ksw]

This is an odd problem, but often the window I'm using will deselect and I can't use any shortcuts until I click on a window again or switch an app. For example: I'm in Safari browsing macrumors so the top of the macrumors window has more color than the other windows behind it, all of a sudden the window with macrumors will look like the other windows in the background and I can no longer type in this message box. If I try command N for a new window nothing will happen. If I click anywhere it goes back to being normal: click on this window to use it again, on the desktop to be in Finder, etc. This isn't a problem with a keyboard or anything, because if I turn off all keyboards, the trackpad, mouse, it still does it. It also happens on all apps. Any ideas? Thanks for the help!

Edited for more info: The application I'm in stays active when this happens (if I was in Photos, then "Photos" is still listed in the upper left of the screen). If I click on any menu item (File, Edit, etc) then the window I was on becomes active/selected again.

 

[ApfelKuchen]

When that window de-selects, is the app you're using (for example, Safari) still listed in the upper-left of the Menu Bar, or is it a different app, like Finder?

 

[Ja Di ksw]

The app I was using is still selected

 

[ApfelKuchen]

Any chance you're using multiple desktops?

 

[Ja Di ksw]

Nope, only 1.