Glad to hear your DS is a little better. Hopefully you will both get some sleep tonight.
I've not heard anything about an eight month check either!
Acorn, I don't think you've got anything to worry about. They all do stuff at different times and in different orders. DD is still nowhere near crawling, but is probably a little ahead with communication. They just have their own areas of expertise they they practice loads.
The way their brains develop they tend to get bursts of development in single areas and the order of those bursts differs between children. So some will be further ahead with language, others with crawling, others with socialising, etc. They all get to the same place in the end, just in different orders. (Hope that makes some sense?!)
Maybe try lots of clapping stuff over the next few days. He may pick it up?
A couple of weeks ago my mum said something about my sister rolling a ball to people at only six months. It had never occurred to me to even give DD a ball to play with! So I got one, and in a week she was rolling the ball, throwing it (quite randomly) and she's now trying to make it bounce.
A question for everyone... What toys are your little ones currently enjoying? DD seems to be outgrowing some of her toys and I feel like I need to get her some new ones. I recently got her the Tomy eggs and she loves those!