Vista - unable to sign into latest live messenger - no error code

I am unable to sign into the latest live messenger, the signing in process
works with the spinning picture and it seys signing in, then it just goes
back to the log in info.

tried with other accounts, an earlier version of msn messenger on the
machine works fine (the one linked with outlook). I have sucessfully signed
in online using the webpage and the connectivity test all say ok. i have
tried uninstalling and reinstalling.

I have norton 2009 and its set to allow windows messenger and the standard
windows firewall is off.

Operating system - windows xp.

please help!