Ninetales, that sucks! Hang in there though. I know it's hard to remember, but eating well and moderately and exercising are important for so many other things than weight gain, so even if they don't seem to be "working", they're still doing you and your bambino a lot of good. It can be sooooo frustrating though, I know.
I've gained about 12 at 25 weeks, which I'm happy with so long as I don't go completely crazy for the next 15 weeks. I'm a little worried because my cravings for sweets and food in general have intensified in recent weeks, so keeping the gain under control may be a little more difficult in this latter half.