I have had my iphone 4 for verizon about 2 months. I have 2 email accounts - gmail and my work email Over the last week or so, When i get out of the subway and regain 3G connection, I get various errors that pop up for my gmail and it's unable to retrieve new messages - sometimes the imap error, sometimes my username/pw is incorrect. All the while, my work email works fine. Once I am either home or at the office and back in a wi-fi environment, the gmail will work fine and update. There are a ton of other message boards out there but they are full of confusing info and SF is definitely the most comfortable for me trying to get this handled!