In my new Dell XPS 8300 the TBS 6921 has had frequent "Code 10" problems.
It was not initialized properly and was shown with a yellow triangle in the Windows Device Manager.
In many but not all cases, a reboot of Windows brought the card back to operation, but it was a real pain.
Inspired by an Amazon customer review I've switched off the Power Management for PCI-Express
and have not had any problems since then.
Steps to switch the Power Management:
In German for Win7 Home Premium: Start, Systemsteuerung, Energieoptionen, Energiesparplaneinstellungen ändern, Erweiterte Energieeinstellungen ändern, PCI Express, Verbindungszustand-Energieverwaltung, Einstellung: AUS
Tentative English: Start, Control, Power Options, Change Power Saving Plan Options, Extended Power Options, PCI Express, Connect State Power Management, Option: OFF
Imroved version (cf. below): Start - Control Panel - Power Options - Power saver - Change plan settings - change advanced power settings - PCI Express - Link State power managerment - Off -OK
Update: 30-Jun-2012
The power settings have not completely eliminated the problem.
My suspicion (!) is that there might be an additional conflict with my Microsoft LifeCam VX-5000, an USB-connected camera.
I deactivated the VX-5000. After that, I've been using my TBS 6921 flawlessly.
Any comments on how to use TBS 6921 and LifeCam VX-5000 together?
How can a LifeCam driver block access to the TBS 6921?