Docucolor 242 - how do I change colorguest network scan template?

I'm trying to edit or add a network scan template from the Fiery Webtools 3 browser interface.

By default I'm scanning to the default guest mailbox and this works fine - I can scan and then retrieve from the guest mailbox through either Fiery Remote Scan or through browsing to the Fiery's IP and clicking on the docs tab and downloading.

I'm trying to change the default 200 dpi to 600 dpi and the default higher compression to lower compression for the "ColorGuest" preset template.

In the Fiery's browser interface, I'm logged in as admin / Fiery.1 , go to scan settings, click edit, adjust these settings, and click save (with the mailbox unchanged, still set to guest) but then get an error "Mailbox Name does not exist: enter valid mailbox name"

I then tried adding a new user to the Guests usergroup through the Configure Tab, java popup, Users and Groups, View Detail, Add User. Rebooted Fiery as prompted after adding user. Tried to adjust ColorGuest template again and set the new user as the mailbox and still I get an error that "Mailbox Name does not exist: enter valid mailbox name"

I then tried adding a new user to the Standard usergroup and followed the above steps, and still get the "Mailbox Name does not exist: enter valid mailbox name"

Any ideas on how to adjust the colorguest network scanning template?