I'm using a Kona LHe card in a Mac Pro, Dual 2.8 Quad Core w/ 8 GB RAM
Playing SD footage works fine, but when I try to play out any HD video through my broadcast monitor, there is a definite lag in the video, and sync is lost. It looks as if it's playing in slo-mo. Doesn't matter if you downconvert the HD signal either, still the same problem.
The card used to be in a G5 2.3Ghz, and worked fine. In fact, I've tried two LHe cards in the Mac Pro and they both have the same problem. So maybe it's a Mac Pro problem more so than a Kona problem
I'm running FCP 7, and have trashed preferences, uninstalled/reinstalled the latest Kona drivers.