Well, I ended up just recovering them, replacing existing files.
it worked for Sent.dbx but when I tried to do the same to Inbox.dbx I got an error message:
FileID: 0000000004 Program cannot copy the following file: c:\WINDOWS\Application Data\Microsoft\Outlook Express\Inbox.dbx (Original filename: Inbox.dbx )
--->Description: The process cannot access the file because
What to do ??
Please help!