I'm finding that when I get stuck that changing up my exercise helps. You don't necessarily need more exercise, just different exercise. I was doing a little walking and DVDs for months last Spring through Fall. In the Fall my weight loss just stopped. I'm now training to walk a marathon and lost a bunch of weight again. Mix it up. Add some ST if you're not already doing that. Try P90X, I love it.
Good job sticking to it through a plateau. That's really hard. I know cause I've been there several times over the last couple of years.