Glyph Firewire disconnects Western JB800 randomly

[Impala]

Hi,
Our Glyph 1U Firewire enclosure disconnects the Western Digital JB800 80GB hard drive randomly.
Unit comes with two IBM drives installed. Western is installed in an identical enclosure (storcase)
I also use some Seagate drives and another IBM, no problems with them.

Both Os 9.2.2 and 10.2.8 has same problem. It says " one of your fw drives stopped resp... try undoing what you did..." thing. Switching the power off/on sometimes helps, sometimes not. I have to reset G4.

I had some problems before with the same drive (damaged files) and then reformat it within Os X with drive setup utility, there seemed to be no problems left.

I'm also going to write to Glyph but I'd like to post here before for a quicker response.

[auxsend1]

Quick things to check:

1. Were all drives formatted in the same manner? Using OS X Disk Utility?

2. Do all drives have their master/slave jumpers set the same? For FW enclosures, they should be set to Master or Single.