I have a new HTPC computer based on new great Intel DH61AG (integrated power supply 19V) motheboard and DVB-S2 tv-card TBS 6925 PCI-Express x1. The card is properly seen in a system. There is no problem with driver instalation (I used v184.108.40.206 and latest v220.127.116.11). After I start any program (AltDVB, SmartDVB, DVBViewer) properly work any channels with vertical polarisation. After changing on channel with horizontal polarisation there is a crash system - the colors just glitters on monitor. After than computer must be reset off.
I used for test two power adapters: 19,5V 4,74A and strongest 19V 7,11A. I have also other card Prof Tuners 7500 USB and working very good with DH61AG mobo.
There seems to be something wrong with PCI-Express bus?!?
tv-card TBS 6925 PCI-Express works properly with two another boards socket LGA1156 (Gigabyte GA-H67N-USB3-B3 and ASUS P8H67-I H67) but... I used picoPSU-160W-XT + 12V 7A power supply.
Have you tried removing the card and any non-essential hardware and updated the BIOS to the latest version for this board? The express method is the easiest if you have a simple system with non-essential hardware removed or unplugged and the antivirus software turned off before starting the upgrade. Sometimes BIOS upgrades are released specifically to address such issues and I recall one motherboard (don't know if it was your model - but you could check on the PDF thats on the download page) has recently had a new BIOS version released to improve TV card compatibility.