DVI is an 8 bit pathway. HDMI is higher than that. I personally wouldn't assume that the switching in the 990 wouldn't discard that below black info. Someone should ask Outlaw. They should be able to find out.

This problem has been reported on AVS with players outputting HDMI then converted to DVI for the display. If the 990 has 8 bit digital switching for DVI, it's very unlikely that it'll pass higher res than that.