Audio echo playing MKV in MediaPortal (but not GraphStudio) (1 Viewer)

[BezzaMP]

MediaPortal Version: 1.2 RC6
MediaPortal Skin: Black Glass (or standard)
Windows Version: Windows 7
CPU Type: Intel ATOM 330 1.6GHz
HDD:
Memory: 4096MB
Motherboard:
Video Card: NVIDIA ION
Video Card Driver:
Sound Card: NVIDIA
Sound Card AC3:
Sound Card Driver:
1. TV Card: Hauppauge Nova-T
1. TV Card Type: DVB-T
1. TV Card Driver:
2. TV Card:
2. TV Card Type:
2. TV Card Driver:
3. TV Card:
3. TV Card Type:
3. TV Card Driver:
4. TV Card:
4. TV Card Type:
4. TV Card Driver:
MPEG2 Video Codec: As in SAF 5
MPEG2 Audio Codec: As in SAF 5
h.264 Video Codec: As in SAF 5
Satelite/CableTV Provider: Freeview UK
HTPC Case:
Cooling:
Power Supply:
Remote:
TV: Panasonic LCD
TV - HTPC Connection: HDMI-HDMI


I have installed the SAF 5 codecs and have a nice stable set up in mediaportal. I have about 6 MKVs working fine, but one is causing me a problem. I've tried ripping the DVD again but the problem persists. The video plays fine, but the audio has an echo right from the start of playing. As I skip forward the echo can get worse of better, but never completely removed. As the title suggests, this doesn't seem to be a problem with the MKV: it plays fine in GraphStudio and VLC with no echo at all.

I've attached my logs if it's any help.

 

[ronzelver]

I have the same with all live DVB-C TV streams and some streaming trailers (Trailers plugin), but not with MKV's?!
It appears to me that some audio streams get in a strange audio processing loop?!?
I am using the digital output to my surround set.