Deirdre - I don't think he is getting too much day sleep - usually one sleep of 2 sleep cycles and 2 more naps of around 45 minutes - so all up around 3 hours.
When he is awake he is happy and just babbling to himself so maybe it is just a developmental spurt and he is "practising" his new words.

Belinda - can't see any signs of teeth yet - and the way he keeps nipping my nipple between his gums I hope they don't turn up for some time yet !!