SCCM OOB Console SOL stopped working

[idata]

When I first provisioned a laptop all of the functionality in the OOB Console worked fine. A couple of days later the Serial over lan connection has stopped working.

In the OOBConsole.log I get the following

GETAMTPowerState fail with result:0x80070576

:IMR_SOLOpenTCPSession2 with user = domain\administrator fail with result: 0x19, description:Authentication failed

:IMR_SOLOpenTCPSession fail with result : 0x00000019.

I'm not sure what has changed to cause this

I'm running Windows 2003 SP2 R2 Ent Server, SCCM 2007 SP2 R2

[idata]

Are you seeing this error if you try other AMT features, such as power control or IDE Redirection, or just when you launch a SOL session?