I've got Debian and an external USB2 HD.

I've used a script:
http://users.actrix.co.nz/michael/usbmount.html
and hotplug support (running with all necessary modules and the 2.6 kernel)
so that when I plug in the device, it gets recognised, the filesystem
recognised and mounted and a little icon put onto the desktop. That all
works perfectly.

However, whenever I try to unmount the device, either by right-clicking
the icon and choosing unmount, or unplugging the HD, I have problems.
Debian doesn't notice when the device is unplugged and throws an error
(saying that it can't find the unmount script) when I choose the menu
option... despite the fact that the path is correct:


I've previously had this exact same setup in Redhat with no problems, so
I'm a little confused as to why Debian won't allow roughly the same thing.

If anyone has any experience with this sort of thing, or just external
USB devices on Debian, then please let me know!

*bump*

I had similar flaky unhappiness with hotplug and automounting USB devices on my Mandrake AND debian hosts so I don't think what you're experiencing is debian specific. It seems more like hotplug and dynamically created devices in /dev don't seem to sync up reliably 100% of the time. Maybe USB overall is still evolving... I dunno.

I finally threw in the towel and disabled hotplug services completely and just "mount /dev/sdaX /mnt/whereever_I_want_sdaX" manually. I have much more consistent results not using hotplug. Probably not what you wanted to hear though.

Good luck!