UR4 have been removed from Download Center, read more about in on the Exchange Team Blog
Paul Cunningham at http://exchangeserverpro.com posted today that there were issues regarding UR4, I just want to highlight about it.
You can read his article here:
And here is one link to the Exchange team blog regarding UR4
If you have deployed it and have some feedback, please share it with us
Feedback (Quote’s from MS blog):
MSFT have escalated it to the Outlook Product team for further investigation.
“After deleting the „servers“ container in one of the old still existing e2003 admin groups through adsiedit, everything’s fine. Public folder content gets replicated as well as the hierarchy.
Regular emails to public folders get delivered as expected.”