Beckles, DLs int'l configured planes have between 48-52 BizElite seats, with 48 on the 763s.
Only thing I can figure is that you were either on a new domestic 767, or one that DL has reconfigured. DL is putting new seats on their planes. The new first class seats are similar to the BizElite seats in appearance and function.
Anybody out there know if DL has, in fact, increased seating on their dom. 763s to 30? That would be great for all of you who travel often with DL and look to upgrade. I do know that on the new 764s, there will be 36F seats, so maybe they are reconfiguring the rest of the 763 domestic aircraft.