I had been trying this on a Vaio VGN-AR11 before, which also didn't work. Now I was using Apple MBP running XP Pro SP2 in Bootcamp.

Neither in Global Record nor in any other function do I get both ff800 routed to DC. I tried different combinations in cabling the cascade, device 1 first and device 2 second, device 2 first and device 1 second in the cascade - always connected via FW800.
In both cases I can choose an additional second device in Input Device Settings, DC then shows two rows of meters, but both show the input signal of the first device. When I open up Input Device Settings again, my settings have been set back by DC, or had not been accepted in the first place.
Anyway obviously I don't get it going with the ff800, DC will show only the first device of any cascade in the meters.

For now I went back to direct routing between the two devices via ADAT.

I'd appreciate very much any hint for wrong/correct cabling of the devices in a cascade or any obstacles, like different cable length or quality.

Two things:

XP demanded a second driver install after connecting the cascaded devices, but certainly there's only one driver in Device Manager.

There had been issues before, when using those two ff800 via Aggregate Devices in Mac OS X and feeding their inputs to BoomRecorder for recording interleaved wav, like distorted sound on several of the recorded channels. Only when I switched back to direct routing via ADAT and recording from a single device only it would work.

So, a wrong choice in cabling or a defect device could as well be the case.

I will try some different cablings tomorrow and get back to report.

Best Regards
Boris Vogeler