MyTv can not open the buffer TV, no video no sound (1 Viewer)

[osso86]

TV-Server Version: 1.0
MediaPortal Version: 1.0
MediaPortal Skin: default
Windows Version: XP SP3
CPU Type: Pentium 4 2.8ghz
HDD: maxtor 80 gb
Memory: 2x512 mb
Motherboard: asrock 775vm800
Video Card: ati 9550 128mb
Video Card Driver: last
Sound Card: sound blaster 1024
Sound Card AC3:
Sound Card Driver:
1. TV Card: hauppauge pvr 250
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: MPV decoder filter
MPEG2 Audio Codec: mpa decoder filter
h.264 Video Codec: ffdshow video decoder
Satelite/CableTV Provider: cable
HTPC Case:
Cooling:
Power Supply:
Remote:
TV:
TV - HTPC Connection:

Goodmorning to all.
When I'm entering in my Tv menu, the preview is black, no audio.
If I click Watch TV (or Live TV) MP responds with a message "can not open the buffer TV, no video no sound".
I saw TV srv perfectly on preview, and the channel scannig was fine.
The proble is just on MY TV.
Anybody can help me?