Can anyone tell me what is wrong, I have set my daily budget on 5 campaings at $12 per campaign checked today and noticed that cost for last day is $80.72 above my MAX budget?
It's not ok and looks like a problem. I would recommend you to turn adwords support. the best way to contact them is via the live chat, you get the answer quick.
It is ok, and it's not a problem. On any given day your budget may go up to 20% above your maximum, but will be evened out over a month to be within budget. http://adwords.google.com/support/aw/bin/answer.py?hl=en-uk&answer=142728