firewire disc dumps 2nd firewire disc

[rocktown]

Hi, I have bought two new firewire disks (same make, 160 and 250 G), both HFS+ journaled, when I connect both, they wont show. When I connect one it will, when I connect the second one, both disappear. When I connect one with a lacie pocket drive, there is no problem, both show. I use a G4 dual 1 Ghz mirror door with tiger. Has anybody got an idea? gr OC