I work for a VERY large IT company and we have been having problems with our Blackberries
Many of our users have been experiencing Sync issues.
Some are not recieving emails, others have lots of unread emails on the blackberry but have all been read in the Email Client and some have emails syncing but not the Calendar!!!
Our 3rd line team seem to think its just general unrelated issues and say that the reconcile setting need to be checked and then the device needs to be wiped and reactivated.
This Does not usually resolve the issue and they just say it is other factors like signal strength(understandable) and battery level (WTF!!)
