I normally have 3G switched off. This morning I switched it on, in a place where I normally used to get one or two bars of 3G reception. When I switched it on I immediately got "No Service". I then switched 3G off and the "No Service" remained (where normally I get the full 5 bars on Edge). I waited a few minutes and still had the same message. I had to hard reset the phone to get reception again.
I updated to 2.0.1 yesterday.