Crap, I've plateaued. Since last week, I've gained 0.4 pounds—which doesn't really mean that I've gained a lot of weight, but it sure does mean I've quit losing it for a week.
I hit this sort of thing when I dieted a few years ago and got fairly discouraged—but I've been reassured by my 20/20 dietician that this is expected and that odds are good that I'll be back on my way to weight loss next week.
Which is fine with me. The averages overwhelm the weekly results, so as long as I keep chugging along with all the exercise, I should be in good shape. Or at least better shape.

I hit plateaues multiple times in the program. For me it was usually either stress or my body getting overly used to a specific workout routine.
Agreed—and this week certainly has been stressful!
I think there's a clothing component to it, too: the gym subtracts 2 pounds off my gross weight if I'm wearing workout clothes, or 3 pounds if I'm wearing street clothes.
I'm not sure about you, but my typical street clothes weigh at least three or four pounds more than my workout clothes, and that would account for the difference since I wore workout clothes last week and street clothes this week.