http://www.aja.com/support/kona/kona-system-configuration.php
This page has the slot configuration for various Mac Pros. Failure to not use the qualified slot can cause performance issues. Determine if the Mac you have (It's always good to mention CPU specs here, BTW) has the LHe in the right slot.
In most cases, as you can see by the page, slot 2 is OK. However, if the Mac is a bit older, you may need to change the expansion slot utility.
You can also compare the slot config to your other machine. Is the BM card in the same slot?
Also, have you downloaded the latest AJA drivers (v8)? I know you said "latest", but a version number helps. The installer also has a conflict checker application. Try that as well. Blackmagic and other drivers may conflict, if installed.
.: michael kammes mpse
.: senior applications editor . post workflow consultant
.: audio specialist . act fcp . acsr
.: michaelkammes.com
