I think you might be seeing something else... The digital bass management is different than that of the analog when using "bypass" mode. I measured the outputs in digital mode, and I think everything was OK, but you might have caught something that I missed -- I did not measure each and every combination of modes and inputs.

There is another issue where the sub output filters the LFE signal, and many think it should not.

Indeed, I have given up. I received a Cary Cinema 11 yesterday, and my 990 is now for sale.