Yep, got that on one of my first merc jobs. I lost 150k on that one. I wasn't being that selective at first. Just avoiding Story missions because they take forever. I was actually on a good streak last night with the territory invasions. I got up to B, never lost money the entire time, but dropped down to C again. I noticed when I took some territory invasion jobs, I ended up sitting in the Sortie room for a while before someone eventually cancelled it. I did finally try the ranked, free battle. And had two pretty good battles against the same person. Apparently we were the only two in ranked battle.