Error -42408 at iTunes store

Hello amsdekins,
And welcome to Apple Discussions!

This issue seems to be with iTunes itself, and more specifically with the latest update 9.0.3. No word yet really on a definite fix, but this older thread does provide a few work arounds that might be able to work for you.
http://discussions.apple.com/thread.jspa?threadID=2321090&tstart=0

B-rock

There were several helpful discussions in this thread which helped me. First I tried closing everything and going to the Finder, chose Go on the menu/ Go to folder./ then type in /Users/Shared/SC Info. This worked a couple of times and might be sufficient for you. For me the problem came back so I right clicked on iTunes in the dock and chose quit. Then I Deauthorized my computer in iTunes. Then I re-authorized it. Next I went to the Applications folder, chose iTunes and from the window on the left hand side clicked the disc-like iTunes icon and dragged it onto the dock. The next time I connected my iPod I did not get the error message anymore. I have not had this problem with my iPhone so I don't know where the bug originates. Good luck.

I've been having this -42408 error problem for weeks. Unable to authorise computer with iTunes store..."try again later". I wasn't able to sync my iPod or do anything, and songs were removed from my iPod (about 100 songs). I tried restoring my iPod and it worked for a day then the problem came back. Talked to a very helpful Japanese guy at Apple who told me to do this...AND IT WORKED!! Evidently my iTunes program was uploaded with a glitch, and had to reload it. He said you have to be extremely careful and follow the exact order deleting and reloading. My music files all reinstalled themselves and everything plays, no errors. (at least not for yet!) this workes for XP but there is a link for other Windows programs. Good luck. (BTW I am not a computer expert so am pleased that this turned out so well.) HUGE SIGH OF RELIEF!

http://support.apple.com/kb/HT1925?viewlocale=en_US

hmmm. problem is creeping back. Turned off automatic sync in Preferences and for the time being things are O.K.
This looks like ut is going to be a constant challenge.