Re: "this session contains media that is not supported by the video peripheral"
 

Do you have any other devices connected to the firewire bus on the computer?

Which codec is used for the videos in these sessions? Do you notice any pattern with a particular codec causing the problem? Do you have a video that will always cause the problem? If so, can you use a free file hosting service to upload it and post link (or send me and email at : vi [at] digidesign [dot] com) so I can check it out?

Re: "this session contains media that is not supported by the video peripheral"
 

No, the only fw device is the mbox2 pro and on the 4 other machines there are mbox pros (the new ones) and canopus 110.

I encounter the problem on 2 codecs I use - it's DV PAL (mov made using QT) on the mbox3/canopus machines and photo jpeg (mov made using QT) on the mbox 2 pro machine. I don't know if other codecs lead to the problem because I don't use any other.
Unfortunately I see the message randomly, no specific movie...

Re: "this session contains media that is not supported by the video peripheral"
 

So you have both your audio interface and the Canopus connected to the firewire bus of the computer? If so - that's likely the problem. You should get a firewire card and connect either the interface or the Canopus to it, with the other device connected to the computers firewire port.

Re: "this session contains media that is not supported by the video peripheral"
 

Do I understand it ok: even if I have both the devices connected to different FW ports (the builtin ones) they occupy ONE FW bus causing the problem? If so then I get it. But I'd like to mention the problems started with PT 8 and a Mac Pro, I don't remember it on my previous machine which was a G5 quad (PCI-e one)

Re: "this session contains media that is not supported by the video peripheral"
 

That is correct - ALL firewire ports on a Mac Pro are on the same bus/controller. The Canopus can be the only device occupying a bus/controller, otherwise problems (like this one) can occur.