Recently my MacBook Air started switching back to the main screen by itself while I was working in a full-screen Window. It didn’t matter which window: Tweetdeck, Screen Sharing, whatever.
This post fixed it for me: https://discussions.apple.com/thread/3922988?start=15&tstart=0. The Google Drive app is evidently updating something in the toolbar.
Fortunately it can easily be stopped:
- Click on the Google Drive toolbar and select Preferences.
- Untick “Show file sync status icons and right-click menu”.
- Press Apply Changes.
No more ghost in the machine! For now…