I know for a fact certain files ARE being checked when you login to live. TRUST ME on this one. As for which files specifically, I couldn't tell you. I detailed how people were getting around the authentication before on XBL (XBE Exploits Forum, somewhere in the pinned xbl thread)... It is because of that flaw these security updates were invented.
I'm not saying that this will solve all your problems. You need to find out what banned you in teh first place and rid yourself of this. As for making youself look 'new' to the servers. This is all that is needed.