I wanted to also point out that we have fixed this issue in TwonkyMedia server 5.1.1-RC2. This release will appear in the next week or two in the Beta section here on the Forum.
DENON has tested this release and confirmed it works properly with both the S-302 and AVR-4308. I suspect it work with other DENON products as well.
If you encounter additional issues like this, please send mail to firstname.lastname@example.org