Maxtor OneTouch II External Hard Drive issue with Leopard 10.5.5

Welcome to the Apple boards
Not all external drives are Leopard compatible and not all are Intel compatible.
Presuming the drive uses the APS and not GUID, that might account for the problem, but I would suspect that it's just not a Leopard compatible drive. It may simply need a firmware update.
Are you trying to connect with FW or USB?

I have an ancient Maxtor 160 GB drive on my G5 for TM and it works fine, but I have never tried using it on my MBPs. The partition scheme is APS, or course.

On the Maxtor page
http://seagate.custhelp.com/cgi-bin/seagate.cfg/php/enduser/stdadp.php?pfaqid=4975
they say the following about Leopard and Maxtor One Touch II:
"2 - This hardware was released prior to the release of Leopard. Therefore, it has not been thoroughly tested in that environment and is not supported by Technical Support."

Message was edited by: nerowolfe

MLast I checked (a month or so ago), Maxtors support site still said Maxtor one touch software (for automated backup) does not work with 10.5.
and advised checking back later.

The drive itself should be recognized by the machine, and should also work with time machine or other backup software.