I have a BES v3.6 with 50 users on it.
All handhelds work fine, but one has big delays for his emails.
He receives his emails about one hour after he received them on Exchange.
I have experienced the same issues with some of users in Oaklahoma. They are recieveing emails with about 30 minutes delay in clusters. RIM, states, the BES server scanning agent might need to reinitialize. Reboot was recommended. I have to wait for sunday to reboot mine. Let me know if it made any difference on yours...
Sohail, my admin said me that after deleting, re-adding the user on the BES, and regenerating the key, all seems to be ok.
I am sorry I cannot ask him to reboot. Sorry...