Plextor 760A wont work on firewire 800 1394b bridge???

[shiftiesb]

I'm using SuSE 10.1 with 2.6.16 kernel, my pioneer DVR-111 works fine on the firewire 800, but the plextor wont. The plextor does however function correctly with a firewire 400 bridge. HELP please, million thank you, I really need to figure this out the plextor is my last hope

[bob11879]

What is the host chipset? 1394b should step down for a 1394a device. Most likely some compatibility issue.