Possible Resolution/Solution: [Worked for me]
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Try deleting all prior email from that hotmail/msn account and then send some test message. And also send the service books again. Hopefully this will help you some of you out.
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*Also note, if you re-add a MSN/Hotmail account that previously supported the option "Synchronize deleted items between this mailbox and my device." this option will no longer be available. And there is no going back. Personally I prefer the old option, but if you prefer real-time push delete the account and re-add. The new way also requires you to login in the BIS every 90 days and confirm you still want to push.
For additional information, please see:
http://www.blackberryforums.com/blac...ion-issue.html