I was thinking about this problem of pooches getting up at the crack of dawn last night - then I remembered an article about this in "Your Dog".
"The dog(s) know that when they bark you appear, feed them, let them out etc.
What you need to do is get them out of the habit. When they start barking get up, ignore them, make a cup of tea and go back to bed.
Come back 5 minutes later and give them their breakfast etc., then on the next morning come back 10 minutes later and so on. This way they won't associate their barking with you getting up and feeding them. You getting up and making a cup of tea and ignoring them will be a bit of an anti-climax for them. Barking no longer works and you've got the dogs beat!!"
This all sounds like a pretty good suggestion to me and has to be worth a go (and you get a well deserved cup of tea out of it).
I really hope this helps.
Marian (& Harv)