I had the same problem under XP, swapped a plain CD player with a new 720a... burnt a couple fine then started giving me the "illegal disc" error. (using
dvd43 with
dvd shrink...)
Updated firmware... no luck....
Got some sony-supported verbatim discs.... no luck...
Updated
Nero.... Still no luck.....
However
Musicmatch Jukebox was giving me problems and would not read from the drive.... then no programs could read from the drive.
Have since uninstalled Musicmatch, Nero and DVD Shrink..... Reinstalled Nero and Shrink and hey presto the drive burns fine at a full 8x on DVD-R and all other programs now read the cd's etc.....
Worked for me?!!