We had a lot of problems with shared files. Ex documents were created in QlikView version 8, migrated to verison 9. Some problems were related to the creator of the shared object left company, so the account was no longer in Active Directory. Or somebody created bookmark BM123, deleted it, somebody else created later new bookmark that got same ID and got lost again.
Most problems were solved in QV9 SR6. But .shared files are a big pain, especially because there is no visibility inside