Currently Being ModeratedFeb 12, 2013 10:05 AM (in response to thatsnotmyname)
When there is this problem on one account but not another on the same computer it most often is a corrupt preference file.
Hold down the Option key when you click on Go in the Finder menu (not in Pages). You will get an option Library on the menu that opens. Click on Library and find the Preference folder. Look for com.apple.iwork.pages.plist. Move the file to the Trash. Start Pages again.
Currently Being ModeratedFeb 12, 2013 10:21 AM (in response to thatsnotmyname)
Adding to Fruhulda's answer, if that one plist file isn't the culprit, there are others that could be causing trouble. In that same User Library folder, there are many plist files that could be corrupt. It doesn't cause any trouble to delete a plist file, so you might as well have at it if the program isn't working anyway. Deleting a plist file just resets certain parameters to what they were before you began using the app.
On my system there are 11 plist files in my User Library having to do with iWork apps.