Ubuntu 9.10 Drive mounter requires password.

This fix is with thanks to:

http://www.shareconnector.com/howto-remember-authentication-mounted-drive-in-ubuntu-910-karmic

To stop the password being asked for the time you can edit this file:
 /usr/share/polkit-1/actions/org.freedesktop.devicekit.disks.policy

sudo gedit /usr/share/polkit-1/actions/org.freedesktop.devicekit.disks.policy

Search for "mount-system" to find:
org.freedesktop.devicekit.disks.filesystem-mount-system-internal
Change "allow_active" from "auth_admin_keep" to "yes"

It all then just works.

See the link above for a better description.