I had a 'no SIM' card message on my phone, which I thought was due to the SIM having not been activated.
an hour after the 3 hour activation dead line, i took the SIM out, turned it aound so that the 'clipped off' section was at the top and not at the bottom, and put it in again... it activated within a minute. i.e. i had put the bottom in the top.
I had thought it was a faulty sim,