I just recently found this bug, when I completed the mission to take the brass monkey to port regal I did not get the 900 xp nor did I get a notification of the missions completion. Please help! and I have accepted the next mission as well. Thanks!
If I remember correctly, you are supposed to deliver the Brass Monkey to the Inspector who is at the entrance to Port Regal (you might have to stop your ship there). The Inspector is then supposed to let you have access to Port Regal and tells you to take the Brass Monkey to the Governor. Check to see what your Quest Journal actually says. Also, next time please include the name(s) of the Quests you are talking about. It makes them much easier to find and, of course, to help you. If you got in to Port Regal (and it sounds like you did), that does sound like a bug.