switching from tv to video: no sound

[sanghoku]

TV-Server Version: built in tv2, not the sql server thing
MediaPortal Version: rc2
MediaPortal Skin: bluetwo
Windows Version: vista
CPU Type: x2 4200
HDD: sata 250gb
Memory: 4x500mb
Motherboard: msi k7neo4
Motherboard Chipset: nforce 4
Motherboard Bios:
Video Card: 7800gtx
Video Card Driver: not too old
Sound Card: realtec (onboard)
Sound Card AC3:
Sound Card Driver:
1. TV Card: wintv pvr-350
1. TV Card Type: analog
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: tried a few
MPEG2 Audio Codec: tried a few
Satelite/CableTV Provider:
HTPC Case:
Cooling:
Power Supply:
Remote: hauppauge
TV:
TV - HTPC Connection:

Hi, very strange problem when switching between TV and video:
1. when tv is playing, switching to videos directly and starting file there, i have no sound of the video.
2. i start manual record of tv (record now button), tv is turned off, switch to watch video file while recording, no sound of video file.
3. watching tv, turn off tv, go to video and play one: i do have sound

it seems to me that if in any way the tv is doing something, i can't start a video file without losing sound. BUT when i program a recordingin advance which happens to start WHILE watching a video file, there's no problem: video plays fine, recording is fine...
i've tried a variety of audio codecs/renderers, but can't find a working combination... it's like the audio codec is busy doing somethig with the tv which interferes with the audio stream of the video i want to play

I hope someone can help me as this is somewhat annoying
(log files in attachment, i switched a few times right before zipping them so i hope the info you need is there...)

[sanghoku]

update: in the new 0.2.3.0 when tv is playing or recording, videos won't even start playing :s