I am not sure this is a bug, but when I retrieve info for a CD from FreeDB and FreeDB reports the CDDB DISCID starting with a zero in the list of search results, that zero will be removed from the front of the ID and appended to the end of the ID when you go to the next dialog.
An example, I have the 3CD set from Prince "One Nite Alone... Live!" and CD2 has as ID
"0D0E8811". When I search on ID, it says in the returned data that the ID is "D0E88110"
EDIT: If an ID starts with more than one zero, every zero will be moved to the end of the ID on the 'Next' screen after the "List of search results..." dialog