can't splitscreen

also adding on that when we try to play MW3 it see the guest account as an regular account and says that  xbox live isnt on for the guest account

Guest accounts aren't granted the same permissions as a full Xbox Live account. As far as your issue with being able to play split screen. I have experienced this first hand on many games. They will let the standard user play as normal, but the guest account cannot connect. This could be due to you are trying to play an online multi player session but the permissions for a guest account are not there. You will have to play local in order for a guest account to play usually.

as you are saying "my recent dashboard update" i am guessing that you are in the beta.

if you are in the beta, please in the future post all questions and / or bugs in the beta forums located at forums.xbox.com/.../default.aspx.

however now that where here if you are in the beta there is a bug that all beta members are suffering, the "unable to sign into guest account split screen bug" this has been noted many times in the beta forums and i am sure that the beta team is dealing with this issue, till then youll just have to wait till the next update.

thanks i was looking for the forum lol