Oulook 2003 dial up sync errors

[Derrick]

we are using outlook 2003 will all current updates
insatlled and are using cashed exchange mode. our
operating system is windows 2000 SP4 with all the current
updates as well. when the user connects and hits f9 to
sync we get the following error in the sync log (i have
run detect and repair and removed and recreated the users
outlook profile) any suggestions??:

18:57:44 Synchronizer Version 11.0.5604
18:57:44 Could not connect to public
folder server.
18:57:44 [8004011D-526-80040115-0]
18:57:44 The Microsoft Exchange Server
computer is not available. Either there are network
problems or the Microsoft Exchange Server computer is down
for maintenance.
(/O=CAST/OU=LosAngeles/cn=Configuration/cn=Servers/cn=CASTM
AIL1)
18:57:44 Microsoft Exchange Server
Information Store
18:57:44 For more information on this
failure, click the URL below:
18:57:44
http://www.microsoft.com/support/prodredirect/outlook2000_u
s.asp?err=8004011d-526-80040115-0
18:57:44 Not downloading Offline address
book files (stored on public folder server).
18:57:44 Synchronizing Mailbox 'Mary Maurer'
18:57:44 Synchronizing Hierarchy
18:57:44 Terminated in error
18:57:44 [80040115-514-0-921]
18:57:44 Network problems are preventing
connection to the Microsoft Exchange Server computer.
18:57:44 Microsoft Exchange Server
Information Store
18:57:44 For more information on this
failure, click the URL below:
18:57:44
http://www.microsoft.com/support/prodredirect/outlook2000_u
s.asp?err=80040115-514-0-921