Fixing damaged Keynote files??

Does anyone know of an existing script to repair the index.apxl.gz file, within a Keynote file packaage, when it gets mis-named or compressed improperly?
See the following for more details on the problem of damaged Keynote files.

http://discussions.apple.com/thread.jspa?threadID=1030216&tstart=64
http://discussions.apple.com/thread.jspa?threadID=1755105

Thanks.