I had a custom 2.0 and I tried upgrading to a custom 2.0.1, ERROR!!!
first, I got the 1602 error, which I thought I knew represented something about the baseband or something, than my 8 gig iphone could no longer be used or anything, then I downgraded itunes to 7629 on my vista, and I was able to install a original 2.0, not custom. Now, if I try to put the custom 2.0 back on this one I get a error no. 20. Why is this? should I be upgrading itunes to the latest version, or should I be doing something else? thanks!