Its very strange indeed.
Scub? Yes
Build? Yes I can build and burn fine. Even Blu-Ray - Without this function I cant double check my work.
Here is my suspician. A combination of OS and this iMac dont play well together with a version of Encore thats now two versions behind. Everything else Adobe CS5.x works fine.
Apple of course except for the "share to DVD or Blu-Ray" function walked away from optical disk. Id have to hear from other 27-inch, Late 2012, users running the same stuff to know for sure.
Its never been happy on this computer, I need to find out others expeience I guess to make sure Im no wastin my time.