lost drives on firewire

I have four drives on USB 2.0(Drobo 2nd Gen) I see all three volumes. If I put it on firewire 800 I only see one. I go back to USB and see all three again. I tried different cables and computers and no luck. Latest firmware. Anyone else see this?

Very strange, never saw this before. One thought, if you are in a daisy chain configuration or using a firewire hub of some sort directly connect to host.

nope, directly to the PC. no hub and on another PC I put in a add-in card and same results. No one has been able to help and of course out of warranty so tech support wont even talk to me.