I received my refund in early Feb, and had to wait until the 1040-X document was made live by TT. I made the amendment this AM and it was rejected immediately. TurboTax rep (super-nice guy, BTW) walked me through my filing, found something I didn't know was an issue, was very patient with all the questions I had, and said I had to wait 'til March 6 to refile because something not on my end still had to be tweaked. Your mileage may vary. I second everyone else's suggestions to wait until until your return is actually processed, not just accepted.
