outlook 2010 rpc over http password prompt

I have an end user problem using Outlook 2010 configured to use rpc over https.  I  have 2 computers configured in this way.  The configuration has been unchanged for several years.  All of sudden, one of the computers started prompting for the password for the account.  The correct password is entered yet Outlook does not connect to exchange.  The other computer continues to connect correctly to the same account.  When the broken computer fails to connect, it eventually triggers the account locking out.

I do not have access to the exchange server(s) or OWA proxy server.  I am strictly an end user in this environment.

Both computers:
     Windows 7 Pro 64bit
     Outlook 2010 SP2
     Not members of the domain

Most articles I have read point to the AUTHENTICATION needing to be set to NTLM.  Both Computers are set this way.

Additional troubleshooting steps taken on the broken system:
      Removed all Credentials from the Credential
       Changed the password for the account.  Can log in via OWA and one Outlook client after changing the password.  One machine still continually prompts for the password.
      Created a new user account on the broken machine and recreated the outlook profile.
      Ran an sfc scan of the broken host, no problems found
      I have created an ssh tunnel for port 443 to the network that is working, edited the local host file entering a static ip of the tunnel as the name of the OWA proxy.  Using this configuration, OWA worked correctly (no certificate issues).  However Outlook failed to honor the "fake" hostname / i[ address and attempted to establish connections to the proxy server directly. (Checked using netstat)
     On the broken machine, the RPCDIAG switch / connection windows only ever shows the connections in a "connecting" state.

I have run exchange servers for years using OWA and rpc over https.  I have setup numerous outlook profiles using rpc over https.  I just happen to be the end user in this case.  I think I have looked in all the obvious places.  I am at my wits end with this one.  As far as I can tell / know, nothing changed on the "broken" computer.

Any ideas on what to look at next?

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Can you interchange the IP addresses of the client machines and test it out? I guess it could be CAS/LB issues.
indivdual-userAuthor Commented:
I cannot.  The 2 machine are in two locations (office / vs home). I did change the IP of the computer having the problem (Office).  It did not change any thing.   Additionally I have been trying to goto https://webmail.domain.com/rpc/rpcproxy.dll.  This is failing on both machines.  However the Home machine outlook is still working.
Sushil SonawaneCommented:
Disable your lan card and enable and check.

Make sure your exchange server and outlook update with latest service pack and port is not block in windows firewall and network.
indivdual-userAuthor Commented:
Solved.  The date was off by exactly one week.  Setting the correct date solved the problem.  Have the incorrect date cause the certificate hand shake not to function properly.

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indivdual-userAuthor Commented:
Fixing the date solved the connection problem.
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