Help with Harmony remote (1 Viewer)

[bobrap]

TV-Server Version:
MediaPortal Version: 1.0 RC1
MediaPortal Skin: AEON Wide
Windows Version: Vista
CPU Type: Intel 3.0
HDD: Lots
Memory: 2Gb
Motherboard: ABIT IP35Pro
Video Card: Radeon X800 Pro
Video Card Driver:
Sound Card: VIA Envy24 HT-S
Sound Card AC3: Yes
Sound Card Driver:
1. TV Card: Hauppauge PVR-150
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: nVidia
MPEG2 Audio Codec:
h.264 Video Codec:
Satelite/CableTV Provider: DirecTV
HTPC Case:
Cooling:
Power Supply:
Remote: Harmony 880
TV: Samsung LN46A650
TV - HTPC Connection: Sub-D

I'm using a Harmony 880 with a MCE dongle. Is there a way that I can stop Vista Media Center from starting/running when I hit, say, the VIDEOS button?