Okay, just resolved some other Audi problems today - so, let's have a go at yours!
It sounds like the box isn't booting correctly, and I have confirmed issues with v2.13 of my DMS tools that means they are broken for now.
I think, there may be a problem with the system part of your cartridge.
Download version 2.12 of my DMS tools (use the 'alternative links' from this link:
http://forum.phathack.com/index.php/topic,1641.0.html) and install them. Pop your DMS in the cradle, and start the tools (Start, All Programs, PhatHack, PhatHack DMS tools).
Once the tools are running, do the following:
Click on DMS Tools Mode
Select your DMS cartridge from the list (if it isn't selected automatically)
Select the latest Audi firmware
Ensure the option 'Install non-hacked firmware' is checked (ticked)
Ensure the option 'Reflash box' is unchecked
Click the button 'Repair DMS (PHTSYS)'.
This will re-format the cartridge's system partition, and put the firmware back on it. Once this is complete (it'll take a few minutes) then eject the DMS correctly and then put it back into the box in the car. Start the car and headunit and then select the CD changer and hopefully it'll all start up (it might take 20-30 seconds).
If it doesn't, then repeat the above instructions but ensure the option 'Install non-hacked firmware' is UNCHECKED. Again, pop it in the car and see what happens.
If we're still no further, don't panic. We
will get it back up and running!
And for your information, I checked with the guys at AudiSRS and the head unit is a Symphony II - not a symphony 11