Autotune determins wrong PID for AC3

for MTV-Central MediaPortal determins PID 33 for AC3 this is wrong and leads to issues:
 x with Skystar2 you get "no signal"
 x with floppydtv you get video but no audio

PID 33 is not a AC3 stream its a User Private Stream.

   PID 33 (0x0021): User Private (0x81)

   PID 4000 (0x0FA0): ITU-T Rec. H.222.0 | ISO/IEC 13818-1 private_sections
   MHP Application Signalling Descriptor:
   Application Type: DVB-J application
   Application Information Table version 3

   PID 4001 (0x0FA1): ISO/IEC 13818-6 type B
   DSM-CC Carousel Identifier: 41, Format ID: 1
   Association Tag: 0x0029, use = 0x0000, Selector = FF FF FF FF FF FF FF FF
   Stream Identifier: 8
   Data Broadcast ID: 240, ID selector = 00 01

ATSC uses 0x81 (User Private Stream) for AC3. BUT DVB uses PES.

so PID 33 is not a AC3 Stream of MTV-Central (it doenst have one)

If you set AC3 PID to 0, MTV-Central is working again.

h4. Additional Information
Tested on Astra 19.2°E
MTV-Central is a german TV-Channel