I have a 3Gs - I upgraded on itunes 3 days ago to maybe 4.02? and this evening to operating system 4.1. However I am having a problem with my email for the past 3 days and thought that this might cure the problem... but no. I can receive emails but cannot send any. The mail is a yahoo.com account and I have tried everything...i'm now thinking of reverting back to the factory settings on itunes - i suppose this will be an operating system begining with a 3 - but will this solve my problem? I would prefer to keep using 4.1 but if there's no solution to the email problem i'll have to revert! any suggestions please!