I received my replacement SIM today which you sent me as my current SIM will soon be obsolete.
I followed the instructions and replaced the old SIM with the new one.I have a very old Sony Ericsson handset, so this meant removing the battery, removing the old SIM inserting the new one putting the battery back in.
On switching my phone back on, it appears to start OK, but the message "Insert correct SIM card" appears on the screen. I have tried switching it off and on again, re-inserting the SIM and trying again - I still get the same message and the phone wont function. Luckily my old SIM still works, but for how long?
I noticed that although the SIM cards are the same size, the old chip is about twice the size as the new one - could this be the problem?