Is the drive formatted ? I would start Gparted to see what partitions are on
it.
Or maybe the drive is defective.

I have several hd's I put in it - all formatted.
This really hacks me off as - it works fine in Windows

I have one external with both a USB and an eSata port.
both work fine on Intrepid and my Phenom II. My guess would be
to check the useability of the eSata port on your box. but then you
said it works fine on windows, so that is a puzzle.

I tested it with windows on the machine machine. I have three eSATA
ports and I have checked them all. Very odd indeed.

Just solved the problem. I hadnt thought about this until now so I
called tech support for the product to figure confer: If you are using a
IDE drive - you can only use USB. If you are using SATA drive, you can
use either usb OR eSATA - but you have to select the jumper for it on
the inside. These drives Im using right now are IDE.

Glad you got it sorted, will have to remember this tidbit. I
normally only use SATA but you never know.

Im getting data off my older IDE drives and I have a 1TB sata drive I
will be moving things to but - that just didnt occur to me about the
cables.

Yes I thought it would be the jumper Wade but had not though about
saying the internal for SATA

Not sure if this has anything to do with anything, but I recently have
been having problems with internal HD's, just all of a sudden one
seemed to go goofy. I removed it and put it in one of my
external's where it worked just fine. BUT the one I put in
that same internal slot then began to have similar problems. So
what appeared to be HD trouble- is apparently more related to the
connecting cable(s) inside the box. Ive not had time to check
this out further.
Just throwin this out in case it gives you any more clues.