Many of you who have migrated or are still migrating public folders from Exchange 2003 to Exchange 2007 or 2010 have run into replication failures due to property validation. This validation was first introduced in Exchange 2007, and I initially blogged about some those issues in this old post on EHLO. I later posted a script on my personal blog that fixes some of those problems, and described another troubleshooting technique here.
While the validation was good in that it kept 'bad' items out of your shiny new public stores, the items usually weren't 'bad' in a way that a user would ever notice. Maybe they had a null Category, or the PR_SENDER_NAME was empty, or the start/end dates on an appointment weren't all in sync. And while my script fixes a few of the problems, some of the problems can't be fixed and the item simply has to be deleted.
For any of you still struggling with these issues, I have good news. Exchange 2010 SP1 completely turns off validation for items in public folder replication messages. Once you apply SP1, any public folder replication problems due to validation will simply go away.
Of course, this means that on your new public stores you might end up with items that have bad Category values and similar problems. If you like, you can still use my script to correct some of those problems, but in most cases the users never notice them anyway.
Exchange 2010 SP1 will make life a lot easier for anyone still migrating public folders from Exchange 2003. We are evaluating a similar fix for Exchange 2007.