the best way to deal with a 1607 will involve following the directions at installshield.
start here:
http://docs.info.apple.com/article.html?artnum=93976
(1) download fresh software installers for itunes and ipod using the links given on that page. save them to your hard drive and run the installation from there.
(2) if you have trouble with the 1607 when you use the fresh installers, click on the error 1607 link, start trying some of the suggestions that they make on that particular page. you may have to do more than one.
if you still keep running into trouble, post back, and tell us what you've tried so far.
good luck!
love, b