"Signing in to .NET Messenger Service failed ...

[JCB]

Getting this error whenever I try to sign in with any
Messenger ID:

"Signing in to .NET Messenger Service failed because the
service could not be found. Please make sure that you
are connected to the Internet."

XP Pro, latest updates
Windows Messenger 4.7.2009

I can sign into the .NET Passport Service thru IE, just
not Messenger.

LinkSys PnP router and ZoneAlarm installed, but neither
are new. I've rebooted and am one step from uninstalling
and reinstalling Messenger.

Any ideas?

Thanks in advance