For roughly over a month I was unable to use Window Live Messenger Mobile on any of my Windows Mobile devices with certain GSM/UMTS carriers. If I had the SIM plugged in from some mobile carriers, it worked fine, if I switched to the SIM of another carrier, the Windows Live Mobile Messenger failed with a notice that the server is unable to handle my request. Even if it was possible to create a new account, for instance after a hard reset, it was impossible to login to use Windows Live Mobile Messenger what it is designed for - messaging.
However, tonight I received a notification from Microsoft that everything should be fixed now and working well again:

And indeed, as you can see above it's working again. I can log into my Windows Live account and get my contacts and buddies displayed; I'm even able to chat with them.

While I first thought it's a problem with some Live account servers, right after Christmas it turned out that this wasn't the problem since it took to long. I have no idea if the failure was related to Microsoft's plans to charge for Windows Live Messenger Mobile later this year but it's fixed now (fingers crossed it stays working).

Some of you reported similar problems and I would like to know if you can use Windows Live Messenger Mobile again now as well? I will ask my Microsoft contacts to monitor the comments here and therefore it would be helpful if you tell us if Windows Live Messenger Mobile is working again, which device, Windows Mobile version, network and country you are using.

Cheers ~ Arne