Sleep (or lack of it) and solids...

I know I've seen other post about babies waking a lot, but I just wanted to see what others think. Ds slept quite well from when he was a bit over two months until he was about six months old. Then he started waking up once a night, then twice and for a month or so now it has been many, many times a night. He is almost nine months old now, still has not teeth, and eats a few solids here and there.

I keep getting advice from well-meaning relatives about feeding him more solids, but I'm wondering if the solids might actually be a culprit in his waking. I guess I started giving him things haphazardly around 7 months. The only thing he really likes are peaches. He'll eat pretty much anything that I give him, but if he's not fond of it he makes funny faces and doesn't eat much. He's definitely interested in table food, though, and he is nursing a lot more lately than he had been for a while. He seems to digest food well, but the past few nights he has definitely had a lot of gas.

Anyway, my thoughts are that he could be teething (someday soon one may poke through), it could be gas and stomach problems from solid foods, it could be that he's excited about learning new things, etc. I guess I don't really know what I'm asking here. Just want to know what people think about his deteriorating sleep habits and what I might be able to do to make him more comfortable at night and get more sleep.

He sleeps in a crib, by the way. Dh does not want to cosleep. He seems to do just as well there (we did cosleep some in the first couple of months), but I have to get up out of bed countless times a night and it's really wearing me thin.