Ok, the easiest fix I've found to kill these store errors is to downgrade to iTunes 10.2.2. The list of bug fixes for 10.2.3 is here, some of these may be deal breakers for a few of you. Another error 10.2.2 killed for me was this annoying pop-up that told me I shouldn't watch 1080p movies on my machine (sounds like marketing got a hold of 10.6.3 before it was pushed out).
I used Pacifist to bypass the 10.2.2 installer and just replaced the 10.2.3 app with the 10.2.2 app. The library did have to be rebuilt and my iTunes preferences had to be set again. If I run into any problems I'll post them.
Here's a couple references for other release features/bug fixes if anyone needs them:
Wikipedia, History of iTunes
Videohelp.com, iTunes Version History
Macintoshgarden.org, iTunes for OS X Installers
I used Pacifist to bypass the 10.2.2 installer and just replaced the 10.2.3 app with the 10.2.2 app. The library did have to be rebuilt and my iTunes preferences had to be set again. If I run into any problems I'll post them.
Here's a couple references for other release features/bug fixes if anyone needs them:
Wikipedia, History of iTunes
Videohelp.com, iTunes Version History
Macintoshgarden.org, iTunes for OS X Installers