Hi all,
I think I'm going to be alone on this issue, but hoping other peoples mileage as this used to all work a treat, oh and still does to a degree.

As many of you know, you can use external devices for display out of video in Logic Pro (as you can with many other DAWs).
My chosen device is a Blackmagic Intensity Pro card... The PCIe version of this

http://www.blackmagic-design.com/products/intensity/

I use it in conjunction with my Fireface800 running off the Firewire800 port on the back of the MacPro 2.8 x 8 core.
Up until recently (i cannot specify when exactly) it was working perfectly, but now, when I switch the vision to the Black magic card, the FF800 goes silent and Logic no longer outputs any audio.
When I reset the audio driver, by changing the sample back and forth in the Logic settings, I can get it working again. Note, than when I switch the vision from the ext display back to the desktop monitors, the audio is unaffected. ie it keeps working.

When I do the same thing with a Babyface, it all works perfectly. 

I have tried reverting back to older drivers for the FF800 (ie 2.75) but it doesn't help... It might be the newer firmware perhaps?? But I can't downgrade that from what I have seen.

Any advice appreciated.