Hi
The bug that Fred was pointed to is Real but may be is not your problem...
You are having only the forms corrupted?
because in this case you have to run any antivirus up to date searching for a possible virus, there are a lot of virusses that corrupt sct files.
In one ocassion i get mi forms corrupted but not only the forms, the pjx, frx, and all the other tables, and this was caused for the bug Fred was telling us.