Magic number checking on storable string failed at blib/lib/Storable.pm (autosplit into blib/lib/auto/Storable/thaw.al) line 366, at lib/MT/Serialize.pm line 46"

this is the error message i receive when trying to rebuild. i'm not too sure what this is related too.

however last week, we lost the main index file and had to replace it with a backup copy. ever since new entries are not being shown on the site even though MT shows them .

any suggestions?

thanks in advance