This is something I've never experienced before. Every minute or so my Mac decided to de-select everything. Examples: - Multicam cutting in Final Cut. Eventually you try to take camera 2 and DOOT - You get the "can't do that" Mac error sound. At this point the keyboard is useless, I have to use the mouse to click Final Cut. (And yes, the menu still says Final Cut Pro," but no windows in Final Cut Pro are selected. - Watching a movie in Quicktime. Hit spacebar to pause. DOOT - Have to click Quicktime with the mouse. (I can't command-tab to it...it's already selected as far as the program switcher is concerned!) - Typing in Pages. Eventually DOOT DOOT DOOT DOOT - You're typing on nothing, silly boy! This is not a case of it switching to another program or the Finder or the desktop. The app in question stays in the menu bar. It's just that every single window in the program is de-selected. This happens anywhere from every 30 seconds to every 15 minutes. It's pretty random, really. Does anyone have ANY ideas? I've been totally unable to Google up anything that sounds similar. EDIT: Things I have that run in the background: Dropbox, Adobe Cloud, and Splashtop Streaming. I'm experimenting with shutting each of them down one at a time to see if they're the problem, but I thought I'd ask if anyone had any other ideas in the meantime or knew of a log somewhere I could read that might tell me what's happening.