I don't trust DVDA to accurately play back the audio that I give it.
Burn it to DVD and play it on a good system to confirm that everything is OK.
My guess is that it'll be just fine.
How did you test in DVD-A? By listening to the stereo downmix? Then it could be expected behaviour due to a Pro Logic compatibilty mode. In this case this would not be a bug.
I dropped the audio on the DVDA timeline and the waveform displayed as unbalanced and the playback through the surround system on the computer was also unbalanced.
I did not burn to a disc yet to check it.