I've traded some email with OPPO on this. They are looking into it. I'll post more if I hear anything from them.

In the meanwhile, I'll toss out a possible "workaround" that occurs to me: use the 7.1 Direct input on the 990. The BDP-83's analog section is quite good (at least on par with my Onkyo 885). That could be a good solution for listening to CD's while they get a firmware update ready that fixes the digital output problem.