Did you get the experience for completing the escort quest?
A couple people with the disk version reported parts of the Trevor/Marcus/Tingalf quest didn't get cleared properly in the log (shorter, less elaborate quests had problems less frequently), though they got the quest rewards.
Did you talk to the statues in Nericon's garden as well as kill all the frogs to open the portal?
I don't recall if getting the key first causes a problem, or not.
