When upgrading to Xbox Live Silver or Xbox Live Gold DO NOT MAKE A NEW PROFILE. Select your current profile and use the UPGRADE option to UPGRADE that profile to Xbox Live Silver or Gold.
Savegames are embedded in user profiles, they are locked down to offline profiles as much as they are to Xbox Live Gold Profiles. If you create a new profile when signing up for Xbox Live Silver or Gold, you will not be able to access your save games through your new profile EVER.
It's also recommended that if you want to change your GamerTag change it in your profile before performing the upgrade, once you've signed up for Xbox Live it's a 800MS point charge (~$10 us) to change your GamerTag.
Edited by twistedsymphony, 10 January 2006 - 04:17 PM.