Hi,
Welcome to the forum.
Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html . Then look down to item #7 about how to post your code.
It will be formatted in a scrolling window that makes it easier to read.
Please post a copy of your circuit with the 5V regulator, in CAD or a picture of a hand drawn circuit in jpg, png?
Are you using the bypass capacitors around the regulator as suggested in the data sheet?
Thanks.. Tom.. 