I have a mac pro 2008 late generation. when i connect 2 red drives simultaneously via fw800 (one to back port and the other to the front port) i get a message of "your drive wasn't ejected properly".
if one of the drives was able to mount while the 2nd one is still initializing, it will unmount shortly after.
after this message, the only way to mount any of the red drives again at least individually is to reboot the system.
i've tried mounting via fw800 a red drive and any other non-red drive like (g-raid, g-tech etc.) together, and it works just fine. only when 2 red drives are connected at the same time i get this issue. (occurs on red drives from different jobs).
i also tried this: connecting a red drive to 1 fw800 port, connecting a gdrive to another fw800 port and then connecting a 2nd red drive to gdrive's 2nd fw800 port. same eject issue occurs with red drives, bud gdrive stays mounted.