Complete search indicates no files are checked out, even though there are

2 possiblilites come to mind...

1) there was something entered in other tab(s) of the complete search (results must match ALL inputs into every field in the search).

2) this may be a case of a miss-leading or incorrect error message. maybe there are files that other user(s) have added to the vault, but not yet ever checked in (not sure if those would show as checked out in the search)

Cory - are you a system admin for your ePDM system?  Unless you're an admin you won't be able to see files that have never been checked-in.  If you are an admin you should've been able to see all files.  Arrange some time to sit down with your admin or do a screen share session and have him/her perform the search.....this way you'll be able to see all files checked-out and can track down those users to have them check-in all files.