The editor prefs often get corrupted. You may need to rebuild the editor preferences to resolve any conflicts.
Hold down the Ctrl+Shift+Alt keys and simultaneously click on the Edit button on the welcome screen. Release the three keys and look behind the welcome screen by closing it. Or hold down the keys whilst double clicking on PhotoshopElementsEditor.exe in Program Files
You should see a pop up box with the words: Delete Adobe Photoshop Elements Settings File?
Click on Yes
Close down Elements and re-open it in the normal way - then wait whilst it rebuilds the preferences.