Problem viewing TV on client machine (1 Viewer)

[thebalance]

TV-Server Version: v0.9.3.20432
MediaPortal Version: 1.0.0.0 RC4
MediaPortal Skin: Blue 3 Wide
Windows Version: Vista SP1
CPU Type: 2.0 Core 2 Duo
HDD: 250gb
Memory: 4Gb DD2 667Mhz
Video Card: built in (Radeon HD3470)
Video Card Driver:
Sound Card:
Sound Card AC3:
Sound Card Driver:
1. TV Card: Hauppage WinTV-HVR3000
1. TV Card Type:
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:
MPEG2 Audio Codec:
h.264 Video Codec:
Satelite/CableTV Provider:
HTPC Case: Silverstone
Cooling: Passive silverstone on CPU, single case fan
Power Supply: Antec Earthwatts
Remote: imon
TV:
TV - HTPC Connection:

I have a strange problem - this morning I installed RC4 on my laptop (brand new Acer 5920G) and set it to connect to the TV server on my HTPC runnig RC3 and the above TV server version. I was most impressed that the TV worked first time.

Unfortunately it is now the evening and I cannot get TV - the first time I turn TV on the button just turns itself off again and the second time it says there is no video / audio.

I don't think I've changed anything and to be sure I've tested with firewalls at both ends turned off - the only thing I've done is to run a backup which has taken all day so pretty sure nothing significant has changed.

I do get the TV channel information and the current program information appears current and I can definitely view the chosen channel on the source machine.

Any assistance much appreciated.

Thanks