adept manager wants to upgrade gusty beta to gutsy

Binary package hint: update-manager

adept manager wants to do 'version upgrade' on gutsy beta now that gutsy final is available. when clicked okay it downloads some stuff (the upgrade tool), starts about it's merry way and then during 'modifying software channels' is highlighted on the list suddenly says 'The system is up-to-date' and that it has therefore nothing to do. Then quits.
It happens every time I do some upgrade with adept manager.

Not very annoying but makes one wonder if one really should upgrade from gutsy beta to official or not... is this explained somewhere? Nothing was mentioned in the release notes as far as I could see.