Certain Windows Become Inactive

Within the last couple of days, whenever I load something like DVD Player, I have to click on it (the DVD window) to make it active.

I am not sure what started causing this. The only thing I can think of is that I cleared out Launchpad since it was full of way too many apps. I reset it today but that didn't fix the problem.

Has anyone else experienced this? Like I said, this has only been happening the last couple of days or so. I have tried restarting my MacBook but that hasn't resolved anything.

EDIT: This problem now seems to have gone away. Not sure what happened but it somehow resolved itself.

I figured out that it has to do with the recent LiveWallpaper update. When I was updating it again a few minutes ago and the app was closed, my DVD Player loaded fine. When I opened LW up again, my DVD Player becomes inactive and I have to click on it before it will become active.