QUOTE(opelcalibra @ Nov 15 2009, 01:24 PM)

just disable live access on the console using parental controls
that way you can still use your live gamertag but when you select it you will get a pop up saying xbox live access blocked.
I just tried that with my legit Xbox 360. Seems this is really working. But the LIVE connection test is still working and this can still mess up your banned 360. I would highly recommend setting a wrong gateway, too.