Since this has been working for you in the past, try deleting the Elements Preference folder. It occasionally becomes corrupted and causes things that used to work right to quit.
With Elements closed, click on your start up icon and then make a quick grab for the Command, Option, and Shift keys. Hold all three down at once until you get a screen asking if you want to delete the Settings. Say Yes.
If this doesn't clear up the problem, repost. Good luck!