We've been running both regular Adwords and Adsense, but shouldn't the daily budget still be the limit of spending no matter the max cpc?
Anybody experienced similar?
If your spend is over your limit for the month Google will credit you the difference.
Quite correct. This is called an 'Overdelivery Credit' and it is applied just before you are billed. It credits you for any clicks that are over your budget, in the period for which you are being billed.
Since the advertising has already been delivered, and you don't pay for it, what you are left with is some free advertising. ;)
BTW, you can see Overdelivery Credit details by going to the 'My Account' tab of your account, and clicking on the 'Payment received' link for the billing in question.
AWA