That's strange, it seems to be playing fine here. Is XMPlay's time display also looping or only the sound is? Do you have "Auto-reconnect" enabled in the Miscellaneous options page, and if so, does it just play 1 second and stop if that's disabled? To confirm that you have the latest AAC plugin, you can go to the Plugins/Input options page to check the version; you should see "Advanced Audio Coding (rev.7b)".
Are you having the problem with other streams or files too?