Ok, this baffles me:
When I first turn on my 360 it says it is not connected.  I try and connect and it says it cant and prompts me to "Test Connection" Now the weird part, when I try to test the connection, it takes me to the "available neworks" page and when I select "wired network" it tells me "To use a wired internet connection, make sure an ethernet cable is connected to both your console and your router or modem"  It is connected.  To make things even weirder, If I just go and play a game or watch a DVD offline after about 30 minutes or more I'll come back to the dashboard and magically I'm connected.  This only started happening recently, when I first hooked it up it worked fine.  I dont have wireless capability on my xbox at the moment so cant go that route.  My wireless is working fine for the most part.  I changed all the settings to the ones suggested on here by furry in the sticky " Gaming and GameFuel Setup Information - XBox Live" and still nothing happens.  I am running the 1.21NA firmware and havn't had a chance to DL the newest one yet.  But for some reason I dont think that is the problem.  As I stated, this problem was not occurring at first, but now happens every I turn on the 360.