I use a MyBook 1Tb FW800 drive from Western Digital as my Time Machine backup, and I also have a FW800 Lexar CompactFlash card reader. My 2011 MacBook Pro only has one FW800 port so I have to daisy-chain the two devices, which both have 2 FW800 ports each.
However it seems to matter in which order I connect the items together. If I connect the drive to the Mac, then the card reader to the drive, the card reader might not show up, or the drive may dismount; I've not really had the time to tabulate all the possible permutations of chain order and port use. Are issues like this common with FW800, and is there some way I can resolve them?