Just remembered this title and 1:1 copies issue so it may affect Imgburn as well.
Mr. Woodcock
This problem only affects 1:1 copiers, such as
Clonecd.
Clonedvd 2.9.1.5 and
Anydvd ripper work fine with Mr. Woodcock.
(I don't know if 6.3.1.5 fixes this problem)
So you need to rip to the hdd first then use Imgburn to build it to an ISO then burn and you'll have a 1:1 copy with no layer break.