Desktop Video software for DeckLink 4K causes FCP X crash

I just purchased the DeckLink 4K Extreme PCI card for monitoring 4K video output via Final Cut Pro 7 and Final Cut Pro X. Initial testing allows for fairly straight-forward 4K output and monitoring with FCP 7. However, FCP X crashes on every launch just after the default project loads. I've tried using both the Desktop Video 9.7.7 software that shipped with the product as well as the 9.9.3 software downloaded from the BMD website. Both cause crashes. Removal of the Desktop Video drivers allows FCP X to launch and play back properly, albeit with no video output to my monitor. As I'm new to this card, I'm at a loss for any detailed level of troubleshooting. I'm running OS X 10.9 on a 2012 Mac Pro 2 x 2.4 GHz 6-core with 12 GB of memory. Thanks for any ideas on troubleshooting or solving the problem.