BlackBerry Enterpise Server 5.0 (With Exchange 2010) stops delivering emails after a few hours

Our setup before used to be like this:
– Exchange 2007 with BlackBerry Enterprise Server 5.0
Everything was working fine and good, but once we changed to Exchange 2010 with the same BES server the problems started coming in.

The BES server would be working fine and good but after a few hours, it would just stop delivering mails. All services would be still in running mode and nothing in the Event log would give a clue to what went wrong. The only solution we found was to reboot the BES server which would get the mails flowing back to the phones for another few hours.

We used the procedure provided by BlackBerry to make sure the BESAdmin account has the correct permissions for Exchange 2010 and even rechecked.

I would like to know if anyone has an idea of what the problem might be and how to fix this.

Any help is appreciated, thanks.

EDIT(add log):
[50079] (07/21 14:24:50.381):{0xA38} 2 user(s) failed to initialize

[30520] (07/21 14:24:50.381):{0xA38} Sending REPORT_HEALTH_SCORE command to Dispatcher,

Health=0x0000000002001505, Mask=0x000000000200150F, Users=2, Servers=0

[30000] (07/21 14:24:50.381):{0xA54} [DIAG] EVENT=Register_thread, THREADID=0xA54, THREADNAME="TimerHealth"

[30000] (07/21 14:24:50.381):{0xA58} [DIAG] EVENT=Register_thread, THREADID=0xA58, THREADNAME="RegistryMonitor"

[40000] (07/21 14:25:05.585):{0xA30} [BIPP] Received datagram, Tag=6448

[45072] (07/21 14:25:05.585):{0xA30} Processed config stream from Dispatcher, Tag=6448

[40000] (07/21 14:25:07.226):{0xA30} [BIPP] Received datagram, Tag=6449

[45072] (07/21 14:25:07.226):{0xA30} Processed config stream from Dispatcher, Tag=6449

[40000] (07/21 14:25:33.759):{0xA30} [BIPP] Received datagram, Tag=6496

[45072] (07/21 14:25:33.759):{0xA30} Processed config stream from Dispatcher, Tag=6496

[40000] (07/21 14:25:36.321):{0xA30} [BIPP] Received datagram, Tag=6504

[45072] (07/21 14:25:36.321):{0xA30} Processed config stream from Dispatcher, Tag=6504

[40000] (07/21 14:25:36.368):{0xA30} [BIPP] Received datagram, Tag=6506

[45072] (07/21 14:25:36.368):{0xA30} Processed config stream from Dispatcher, Tag=6506

[40000] (07/21 14:25:37.493):{0xA30} [BIPP] Received datagram, Tag=6509

[45072] (07/21 14:25:37.493):{0xA30} Processed config stream from Dispatcher, Tag=6509

[50000] (07/21 14:25:37.915):{0x15E0} Controller: closing

[50000] (07/21 14:25:37.915):{0x15E0} Controller: Requested to stop

[50106] (07/21 14:25:37.993):{0x19A4} Stopping BlackBerry Mailbox Agent 2 for Server WEB01

[30000] (07/21 14:25:37.993):{0xA38} [DIAG] EVENT=Unregister_thread, THREADID=0xA38, THREADNAME="SCS"

[30000] (07/21 14:25:37.993):{0xA54} [DIAG] EVENT=Unregister_thread, THREADID=0xA54, THREADNAME="TimerHealth"

[40000] (07/21 14:25:37.993):{0xA30} SRPClientSessionReceiver thread stopped

[30000] (07/21 14:25:37.993):{0xA30} [DIAG] EVENT=Unregister_thread, THREADID=0xA30, THREADNAME="BIPPa_ClientSessionReceiver"

[30293] (07/21 14:25:37.993):{0xA34} SRP connection dropped

[30293] (07/21 14:25:37.993):{0xA34} [BIPPa] Connection dropped, Error=0

[40000] (07/21 14:25:37.993):{0xA3C} BIPPa_ClientReceiver thread stopped

[30000] (07/21 14:25:37.993):{0xA3C} [DIAG] EVENT=Unregister_thread, THREADID=0xA3C, THREADNAME="BIPPa_ClientReceiver"

[40000] (07/21 14:25:37.993):{0xA34} SRPClientSession thread stopped

[30000] (07/21 14:25:37.993):{0xA34} [DIAG] EVENT=Unregister_thread, THREADID=0xA34, THREADNAME="BIPPa_ClientSession"

[40507] (07/21 14:25:38.914):{0x15E0} ExtUDPLogThread: Code on closing = 0

[30000] (07/21 14:25:38.914):{0x15E0} [DIAG] EVENT=Unregister_thread, THREADID=0x15E0, THREADNAME="ExtUDPLogThread"

[40000] (07/21 14:25:39.461):{0xA1C} [EXTS] BlackBerry Extension(1) disconnected.

[30000] (07/21 14:25:39.461):{0xA40} [DIAG] EVENT=Unregister_thread, THREADID=0xA40, THREADNAME="StarterThread"

[30000] (07/21 14:25:39.461):{0xA44} [DIAG] EVENT=Unregister_thread, THREADID=0xA44, THREADNAME="StarterThread"

[30000] (07/21 14:25:39.461):{0xA48} [DIAG] EVENT=Unregister_thread, THREADID=0xA48, THREADNAME="StarterThread"

[30000] (07/21 14:25:39.461):{0xA4C} [DIAG] EVENT=Unregister_thread, THREADID=0xA4C, THREADNAME="StarterThread"

[30000] (07/21 14:25:39.461):{0xA50} [DIAG] EVENT=Unregister_thread, THREADID=0xA50, THREADNAME="StarterThread"
[30000] (07/21 14:25:39.461):{0x9FC} [DIAG] EVENT=Unregister_thread, THREADID=0x9FC, THREADNAME="GlobalStatsThread"

[30000] (07/21 14:25:39.461):{0xA00} [DIAG] EVENT=Unregister_thread, THREADID=0xA00, THREADNAME="SCSWorkerThread"

[30000] (07/21 14:25:39.461):{0xA58} [DIAG] EVENT=Unregister_thread, THREADID=0xA58, THREADNAME="RegistryMonitor"

[30000] (07/21 14:25:39.461):{0x9E4} [DIAG] EVENT=Unregister_thread, THREADID=0x9E4, THREADNAME="PFContactMonitor"

[30065] (07/21 14:25:45.756):{0x19A4} BlackBerry Mailbox Agent 2 for Server WEB01 shutdown complete
====== END OF LOG ======