From what you said, it sounds like the files are intact on your hdd.
Is this correct? Are you able to view the movie from your hdd with a player like VLC,
Powerdvd, etc., etc.
Did the bank disc start to write at all? Is it still usable?
Like SJ said, a burn log would help a lot.
The default location for the log is as follows:
C:\Documents and Settings\
Administrator Name\My Documents\DVDFab\Log