C.S.
I know it may be hard, but he's shown you he can sleep through the night, so if you can let him cry it out a little that might help. I've found the book, Baby Wise, on sleeping to be very helpful. He might be teething. That may be waking him up. Is he drooling a lot more or a little stuffy? If you can get him to put himself to sleep without rocking that might help. There is no reason he shouldn't be a good sleeper all around, but every baby is different! Good luck!