It might have been because I asked for too many things, but none of the things I asked for have been awarded. If I understand it correctly, asking for something like a certain day off can't hurt you if it isn't awarded.
I did experiment by asking for certain overnights, however I only gave 20 points to this while giving 800 to days off. If I understand it correctly, the system would have to give me 40 overnights in the requested city before it costs me a day off.
No other MSP fo's got a significantly worse than normal PBS award this month? If I'm the only one, I definately have to change my bid, but if everyone noticed a drop in days off, then maybe it was more due to the patterns than my bid.