I've had a ticket w/RIM since June 12th for delays when messages are sent to my vzw.blackberry.net
Every few days, between 1 PM and 7 PM Eastern, some messages are delayed up to 3 hours. The problem has been elusive for sure. In any case, RIM continues to research the problem. This is a BIS 2.0 problem with the hosted mailbox on the RIM network.
If this continues, I will request RIM move my mailbox to another server to see if that helps.