So what do you do when your baby gets positively hyper when tired?

DS has always been this way - even when he was a few eeks old he'd get hugely overstimulated and couldn't fall asleep. Now at 9 months he's much, much better, but still has difficulty settling sometimes as he's constantly twitching. Some nights he'll pull at his face and hair, scratch the sheets, bash his head against our shoulder/the mattress, kick his legs, anything to keep himself awake it seems. He does realise that sleep is good now, and when he's tired he's grateful to be fed/rocked off to sleep most days. But this twitchiness is really difficult to deal with patiently.

Also he's taken to waking at a similar time every night and being awake for a couple of hours (although exhausted and clearly trying to get back to sleep) - he groans and writhes and kicks and sometimes cries, for no obvious reasons. Sometimes he'll have a huge fart and then settle, or sometimes he hums (seems to be a teething thing) but mostly there's no reason. Calpol is hit or miss, ditto teething powders. We cosleep although he happily starts the night in his cot.

He naps really quite well now - today he had 2.5 hours first thing, an hour at lunchtime and then 45 minutes or so this afternoon, and was shattered by bedtime at 7.

Any suggestions? He's a terrible sleeper and I have just got to live with that but he makes it very hard to stay patient sometimes.

*weeks old, I mean. Freudian!

Bump - my DS is like this, and always has been (17 weeks old now). He scratches his face like mad in the night - wakes up looking like he's been attacked by a determined hamster.
We have real trouble winding him down, and even more trouble trying to get him to nap during the day. He used to settle with a dummy, but isn't having any of it any more. Currently the only thing to settle him is either feeding to sleep or being walked up and down.