If you are having problems in a particular User then it usually is the reources of that user ie the .plists and the fonts.
You haven't said how you had the problem again.
Did you attempt to open the same file again in Pages or did you first try to just open a clean Pages template?
As for the Genius Bar, just tell them everything, have the problem file available, but don't try it first. You try and narrow in on the problem, as in open in different User to demonstrate that Pages is OK. They usually consult here anyway.
Try what works (if anything) then estabish the problem by eliminating other possibilities.
Last resort is to delete Pages and all its system files and reinstall. That usually fixes it:
http://www.freeforum101.com/iworktipsntrick/viewtopic.php?t=105&mforum=iworktips ntrick
Peter