Same deal. However, I can't even get the OEM disc to mount at all-- it just gets ejected.
iMac 3.06 27, 16 GB RAM, Mavericks 10.9.4, DVD version 5.8.0
I tried multiple pre-recorded (i.e., "bought as new, in-store or online, from OEM") DVDs, including Star Trek: TNG from any season, several movies from different companies/production years/studios. All are cycled for about 10-30 seconds and then ejected. All discs are pristine, and I carefully checked them with an air duster before inserting them in the slot. Ok, this is starting to sound pornographic. Queue the cheesy music...
Note that music CDs are accepted and read by the same machine/setup.
I have to say, I'm really noticing a serious downturn in customer service response and overall product quality ever since Steve is gone, not that I strongly believe that to be the reason. It's just hard to ignore the correlation even if it doesn't mean causation.