It appears some older devices (in this case a Sony J-10 Betacam player) with firewire 400 ports are not recognized by the Mac (FCP, FCPX, AJA VTR Exchange, etc) when using an Apple firewire 400 to 800 or Thunderbolt adapter.
The devices work as expected if you can find a Mac with a firewire 400 port.
Anyone else experience this problem? If so, how did you solve it? A particular firewire hub perhaps?
Thanks!