Hi James,
try this out:

On the workstation:
sudo
passwd partimag

Then you have to create a dir with write permission for the user "partimag".
Then start partimaged with the target-dir (I think parameter -d should do this?)

Then on the laptop:
sudo
partimage

If you are prompted for user and password you can enter username "partimag" and the matching password!

This should work!

Regards
RFC 0815