Was this ever explained? I have uddeim installed and logged in as superadministrator it is fine, but logged in as another group if I click on the link in the module or on the title of a new message I get the "You are not authorized" message. I have jaclplus, but my understanding is that this will work with jaclplus.
Update: The problem seems to be with the itemid. There were two itemids, only one of which would work for registered users (either worked for admins). I ended up hardcoding the correct itemid in the module and now it works, but I would still like to understand why this was happening.