E72 not synching after move to Exchange 2010

Question

My company has hundreds of E72 users that synchronize with Exchange 2007.
After we installed Exchange 2010 we had problems because the E72 phones would not get redirected to the legacy.domain.com URL.
We finally had to fix this with a workaround on our reverse proxy.
But now when we move the mailbox to Exchange 2010 the user is able to send out new emails and check the global address list, but new emails are not appearing in the mailbox on the phone.
Updating the firmware (if available), or recreating the Mail for Exchange profile will cause the phone to start syncing again, but this is not a very user friendly solution.
Does anyone know what is causing this? Or better yet, have a solution for this issue?
So far all iPhones, Windows Mobile and Android phones are syncing correctly after the migration.

Answer 1

Bad/Corrupt Rules can also cause migration failures so you might check that as well.
Depending on the # of mailboxes you have to work with another option would be to take an offline copy of the database (EDB/STM) and use a 3rd party utility like Lucid8's DigiScope to open the database offline.  Once you have access to the data you
could dial-tone the DB, then execute the MB move which will go fast since the DB is pretty much empty.  Once completed use DigiScope to inject/migrate the data directly from the offline 2003 database into the production Exchange Server. 
Search, Recover, & Extract Mailboxes, Folders, & Email Items from Offline Exchange Mailbox and Public Folder EDB's and Live Exchange Servers or Import/Migrate direct from Offline EDB to Any Production Exchange Server, even cross version i.e. 2003 -->
2007 --> 2010 --> 2013 with Lucid8's
DigiScope