CDR

I have a CDR that had a session opened with Adeptec Direct CD Wizard. After files some .xls files were written to the CD. The session was closed. Later on, a new session was opened on the same cd to add some files. Upon closing the last session, theoriginal .xls files no longer show up on the CD. It seem that the allocation table was re-written without the original contents. I have done this many times in the past, and never had a problem. I need a utility that can read the entire contents of the CD. I tried the Scandisk that Adeptec has with their softwar, but it does not do a through scan. Any suggestions?