“iTunes could not sync with Yahoo! Address Book because an Internet connection is not available.”
For some iPod Touch and iPhone owners, iTunes will regularly throw an error while trying to sync with the Yahoo address book. It's a goofily incorrect error message in that it happens while you are patently connected to the internet. Arg! If you’ve been searching for a solution for this problem, I think I've found a way to get around it.
The root of the problem seems to be fairly simple -- with emphasis on "seems". What I found is that if I re-enter my Yahoo! password then the sync will go successfully. So; it seems that iTunes is forgetting or losing my Yahoo! password.
Part of the work around, then, is simply to re-enter your Yahoo! password. But why is it forgetting the password (if that's really the problem) and how do you make it stop losing it?
A search of the web for solutions found that there are a lot of people experiencing this problem with iTunes but also that they -- or we -- are all also Windows users. There are a few iTunes problems that only pester Windows-iTunes users. One of these problems -- the "iTunes Hangs on Exit" problem -- is particularly disruptive and requires that iTunes be forced to exit "uncleanly" as the techies say. This makesit not possible for iTunes to properly store away its configuration data -- possibly including the Yahoo! logon information.
Having already come up with a workaround for the "iTunes Hangs on Exit" thing, I ran a few test runs getting iTunes to crash or having iTunes exit cleanly by following the workaround for "hangs on exit" and here's what I found:
If you enter your Yahoo! password in the sync configuration before you do a sync, then the sync with Yahoo! will probably be successful. Then, if you follow the "hangs on exit" work around so that iTunes will exit cleanly, then restart iTunes and sync you'll happily find that iTunes will again synch Yahoo! successfully.
This isn't a fix; it's a workaround. It will still fail once in awhile until Apple steps up to fix the problem for real; but if you re-enter your Yahoo! password and be sure to exit iTunes cleanly, then the sync will work more than 90% of the time.
Good luck! It works for me.

