Every time i try to burn a dvd it will burn for like four hours and then say "error: buffer underrun" or something of that nature. does anybody know how to burn a dvd successfully with this program?

make sure you're using a DVD-R not a DVD+R. Also if it's an old version of iDVD you're using, you might want to consider updating. Try checking out the support site at apple.com, it's very good.