I've got the same problem - SIM card symbol with a red line through it, showing I have reception when I don't, etc - is this common?

I'm convinced this started after an OTA update - probably for ConBoy as it seemed to update very regularly, but I can't prove it. However, I reflashed the phone and the eMMC and it was still a problem, so I'm guessing it's a hardware issue.

When my SIM card is in the holder you can push it downwards into the PCB, there's a good 1mm-2mm of movement there which in my mind means the SIM can't be having the best connection.

I folded a bit of cardboard under the battery but not sure this will work forever - has anyone had this successfully repaired by Nokia? What did they do?