http://i39.tinypic.com/25uiq94.jpg level 38!

So.. instead of the game telling me that I "must complete more missions before I can accept this one", it should really have been telling me: "You cannot accept any more quests because your quest log is full". Because that's what the problem was.

So I'm a level 37 trooper. I have a level 36 class quest that says "travel to Quesh and speak to so-and-so". When I get to Quesh, there's a man standing near the orbital shuttle offering a quest which I cannot accept: "You must complete more missions before doing that". I also can't take the shuttle to the surface of Quesh because it says I need to be inoculated by a medical officer. What quest did I miss? What do I have to go back and do? Please help!