bad capture due to luma signal on velocity HD

Hi all,

We have a capture problem. When we try to capture on VelocityHD V9.1.65, the colors of the image aren't right, green bars are on top of the image, and it looks very very noisy. Every other function is working well.
The problem is we've reinstalled the computer, and from this point it started bad capturing. Taking a close look in the vectorscope, we've discoverd the luma channel is distorted. While the Cb and Cr signal is still ok.
We've tried to reinstall a lot of times different altitude drivers, but none of those gave us a solution.

This is our current config, read in the leitch altitude hardware manager...
---------------------------------------------------------------------------
Altitude Hardware Manager Version: 1.3.0 Build 101

Current Video Standard: HD 1920x1080 - 25PsF

----- Altitude Hardware Drivers -----
LtvDdr.dll: 1.3.0 Build 101
LtvMedia.dll: 1.3.0 Build 101
LtvDrv.sys: 1.3.0 Build 101
HpxDrv.sys: 1.3.0 Build 101
LtvFS.sys: 1.3.0 Build 101
LtvService.exe: 1.3.0 Build 101
LtvVfwCodec.dll: 1.3.0 Build 101

----- Altitude Hardware -----
Firmware Version: 2006.7.5.1
PCB Rev: 2.0
Hardware ID: LHTI0209006025

----- Altitude Hardware Options -----
DVE Module: Not Installed
Dual SCSI Module: Present
Auxilary SDI Card: Not Installed
---------------------------------------------------------------------------

Could it be a hardware failure, due to the movement and reinstall of the computer?
We've tried already to replug the leitch card.
Anybody any ideas? I have to admit I'm new to this soft- & hardware, so forgive me any stupid questions. I have a screenshot of this problem, but I don't manage to put it somewhere here.

Thanks in advance.

Lieven