You're not the only one affected by this, as a
Google search reveals.
I get the same message, as I posted about
here a month ago.
quote:
Originally posted by http://help.msn.com
Depending on your country or region, you may be required to purchase mobile messages to send instant messages to mobile devices.
It may have been stopped in some countries.
Try posting on the
Windows Live Solution Center and the Messenger support team should get back to you with an answer.