When troubleshooting to figure out why something that used to work right doesn't any more, delete Preferences as your first line of defense. This may not cure the problem, but for many it's the magic key. On your Mac, with Elements closed, click on the start up icon and then make a quick grab for the Command, Option, and Shift keys. Continue holding all three down until you get screen asking of you want to delete the Settings. Say Yes.
If this doesn't clear up the problem, repost and give more information about your operating system and hardware specs. Good luck!