This has been a problem to me, too. I can never fall asleep, and I'm one of those people that is a serious sleeper. It used to be my best quality!
I've just never had any sleep problems, and now I can't fall asleep for anything, and I do wake up occassionally, which I never used to do.
I don't know if you've cut out caffeine or not, but be careful about drinking it later in the day. It really seems to effect me now that I'm on Atkins.
I'm with you -- if this is a side effect, I can live with it, too. The benefits definitely outweigh this problem!