No agents showing

Hi, I've gone though the process of creating a Windows Service agent but after the process completes no agents show up in the Administration Console.  The first agent I created showed up as Disconnected, then subsequent times no agent appears in any of the tabs.  I've tried creating the agent under a variety of accounts (SYSTEM, a service account and an administrator account) by this does not appear to make a difference.  I'm running it inside a VMWare Player VM and have restarted the virtual machine after any changes to the user accounts.

I've checked the logs and the wrapper.log file shows the following when I try to create an agent:

INFO   | jvm 1    | 2011/06/24 09:05:13 | Registering on server http://MagCommServ01, AgentDetails{Name='MagCommServ01', AgentId=null, BuildId=null, AgentAddress='null', AlternativeAddresses=[192.168.1.13], Port=9090, Version='17834', PluginsVersion='NA', AvailableRunners=[simpleRunner], AvailableVcs=[], AuthorizationToken=''}
INFO   | jvm 1    | 2011/06/24 09:05:13 | [2011-06-24 09:05:13,519]   WARN - buildServer.AGENT.registration - Call http://MagCommServ01/RPC2 buildServer.registerAgent3: org.apache.xmlrpc.XmlRpcClientException: Server returned incorrect status code: 500 Internal Server Error  
INFO   | jvm 1    | 2011/06/24 09:05:13 | [2011-06-24 09:05:13,519]   WARN - buildServer.AGENT.registration - Connection to TeamCity server is probably lost. Will be trying to restore it. Take a look at logs/teamcity-agent.log for details (unless you're using custom logging).  
INFO   | jvm 1    | 2011/06/24 09:05:16 | Registering on server http://MagCommServ01, AgentDetails{Name='MagCommServ01', AgentId=null, BuildId=null, AgentAddress='null', AlternativeAddresses=[192.168.1.13], Port=9090, Version='17834', PluginsVersion='NA', AvailableRunners=[simpleRunner], AvailableVcs=[], AuthorizationToken=''}

The last line is then repeated.

The agent log has the following when the agent is created:

[2011-06-24 09:05:10,318]   INFO -    jetbrains.buildServer.AGENT - Loading agent versions file from: C:\BuildAgent\system\.teamcity-agent\teamcity-agent.xml
[2011-06-24 09:05:10,318]   WARN -    jetbrains.buildServer.AGENT - Agent versions file does not exist: C:\BuildAgent\system\.teamcity-agent\teamcity-agent.xml
[2011-06-24 09:05:10,320]   INFO -    jetbrains.buildServer.AGENT - Build Agent version: 17834, plugins signature: NA
[2011-06-24 09:05:13,374]   INFO - t.AmazonInstanceMetadataReader - Amazon is not available. Amazon EC2 integration is not active: Failed to connect to http://169.254.169.254/2009-04-04. The host did not accept the connection within timeout of 3000 msThe host did not accept the connection within timeout of 3000 ms
[2011-06-24 09:05:13,375]   INFO - .amazon.agent.AmazonProperties - Fetched AmazonEC2 instance metadata:  
[2011-06-24 09:05:13,379]   INFO - zon.agent.AmazonMetadataChecks - Amazon EC instance metadata contains no keys
[2011-06-24 09:05:13,379]   WARN - .amazon.agent.AmazonProperties - Fetched Amazon EC2 instance metadata does not contain required values. Probably this agent was not started inside Amazon EC2. Is proxy server used?
[2011-06-24 09:05:13,393]   INFO - rectories.DirectoryCleanerImpl - Cannot locate .old for path 'C:\BuildAgent\temp\cache'. Deleting files in place.
[2011-06-24 09:05:13,394]   INFO -    jetbrains.buildServer.AGENT - Start build agent
[2011-06-24 09:05:13,406]   INFO -    jetbrains.buildServer.AGENT - Agent Web server started
[2011-06-24 09:05:13,425]   INFO - agent.impl.AgentPortFileWriter - Writing agent runtime file to C:\BuildAgent\logs\buildAgent.port
[2011-06-24 09:05:13,426]   INFO - agent.impl.AgentPortFileWriter - Launcher version is 17834
[2011-06-24 09:05:13,426]   INFO - agent.impl.AgentPortFileWriter - Writing agent runtime file to C:\BuildAgent\logs\buildAgent.port :DONE!
[2011-06-24 09:05:13,426]   INFO -    jetbrains.buildServer.AGENT - Build agent started
[2011-06-24 09:05:13,427]   INFO - agent.impl.AgentDetailsFactory - Build agent ownAddress will be defined by the server. Define 'ownAddress' property in the conf/buildAgent.properties file
[2011-06-24 09:05:13,439]   INFO - buildServer.AGENT.registration - Registering on server http://MagCommServ01, AgentDetails{Name='MagCommServ01', AgentId=null, BuildId=null, AgentAddress='null', AlternativeAddresses=[192.168.1.13], Port=9090, Version='17834', PluginsVersion='NA', AvailableRunners=[simpleRunner], AvailableVcs=[], AuthorizationToken=''}
[2011-06-24 09:05:13,519]   WARN - buildServer.AGENT.registration - Call http://MagCommServ01/RPC2 buildServer.registerAgent3: org.apache.xmlrpc.XmlRpcClientException: Server returned incorrect status code: 500 Internal Server Error
[2011-06-24 09:05:13,519]   WARN - buildServer.AGENT.registration - Connection to TeamCity server is probably lost. Will be trying to restore it. Take a look at logs/teamcity-agent.log for details (unless you're using custom logging).
[2011-06-24 09:10:47,889]  DEBUG - brains.buildServer.NetworkUtil - Found Network Interfaces: [/192.168.1.13]

I have edited the log4j config file to output the debugging info so the log has the request xml but no response.