Outlook 2003 Send/Receive Issue

[Joe_C]

Hello everyone and thank you for reading my post!

CLIENT INFORMATION:
-Dell Latitude C840 (P4 1.7Ghz, 512MB, 30GB)
-Windows XP Pro SP1a
-Microsoft Office 2003 Pro

SERVER INFORMATION:
-Compaq ML530G2 (Dual P4 Xeon, 1GB, 60GB) RAID 5
-Windows 2000 Server SP4
-Exchange 2000 SP3 w/ Post SP3 Rollup

This client is having send/receive issues with Outlook
2003...
He is configured to use cached exchange mode and is set
to login with the default: "Kerberos/NTLM Password
Authentication"
This person uses the Cisco VPN Dialer to connect to the
corporate network (Cisco PIX 515e) and once connected, he
can ping the exchange server by IP and FQDN.

He can actually send and receive e-mail... it's just
every now and then he will receive one of the following
error messages and his laptop will completely "lock up"
at which point he will need to eject the battery from the
laptop and reboot.

----------------------------------------------------------
Task 'Microsoft Exchange Server - Sending and Receiving'
reported error (0x80040115) : 'The connection to the
Microsoft Exchange Server is unavailable. Outlook must
be online or connected to complete this action.'

Task 'Microsoft Exchange Server' reported error
(0x8004011D) : 'The server is not available. Contact your
administrator if this condition persists.'

Task 'Microsoft Exchange Server - Sending and Receiving'
reported error (0x80040115) : 'The connection to the
Microsoft Exchange Server is unavailable. Outlook must
be online or connected to complete this action.'

Task 'Microsoft Exchange Server' reported error
(0x8004011D) : 'The server is not available. Contact your
administrator if this condition persists.'
----------------------------------------------------------

Please note that he was successfully using Outlook XP
from the same location with the same hardware.

Any help would be greatly appreciated!!

Thanks,

Joe_C