I can log in to my live id account, but not via Zune on the WinXP desktop.
Error is (localized): Could not establish a secure channel. The certificate is revoked.
Zune is up to date, time on machine is correct, IE8 cache has been cleared, IE8 has even been reinstalled, machine has been rebooted. I also tried the Zune Media Collection Reset Tool, all to no avail.
On my other machines (Vista and Windows 8 Preview) there is no error.