x-box issues

[wezzer]

has any one had any issues whilst playin on x-box live ?
i keep getting this message
you must have an active network connection to play online or systemlink matches"
and it wont let me play ( COD4 ) until i go back to the main screen and then go back in under singleplayer, x-box live then we are in , for about 10 minutes then it does it again.
just wondered if anyone else has experienced this ??? its really starting to feck me off now