^ I am using a Vodafone 3G SIM with the 400R. I had no issues. I had to wait a day or two for the new SIM to be activated, but once it was the device worked seamlessly. It already has the settings for most (if not all) Indian telecom providers, so I just had to turn it on, connect it and start using it. The only thing I meddled with was the WiFi settings so that it's not open for others to steal. As far as your 2G problem goes, are you sure you have subscribed for a 3G plan with Vodafone? I would try three things:1) Check your settings on the 400R - there's somewhere where you can choose 2G Only, 3G only, 2G + 3G - perhaps that might be on the wrong setting.2) Check if you are getting the same result in different localities of your city. Perhaps where you are using it from has poor network coverage.3) If the above two don't solve it, go to a Vodafone store and show it to them.