Much ado about very little, I guess. The two instances--one where it worked and one where it didn't--had to do with context: the one that didn't work was initiating a process. The other was just looking to see if it was running. To make the one that didn't work, work, I simply needed a pause before ...

I can focus on a folder of images, send a ctrl-a, then send enter. All the images will open in a slideshow mode as you'd expect. But to then take the slideshow to full screen by sending a f11, the images folder instead goes full screen. Regardless of what I've tried so far, I cannot switch focus to ...