I have an ancient UK Nokia 1100 that I've had for 14+ years, and it still works very well. It's a Virgin UK phone, and here in NZ it piggybacks onto Vodafone network. However, the roaming charges increased significantly just the other day, so I thought I'd buy a local SIM. I read that Vodafone have a specific 2g SIM card, and I asked for one of these at the Vodafone store the other day. However, the message on boot-up says "SIM not OK". The assistant suggested the phone may need unlocking. I checked with Virgin UK, and they say the phone was never locked. I notice the Vodafone cardboard envelope that comes with the SIM says 4g, and I understand it should be backwards-compatible with 2g. However, when I compare the two SIMs, although they are a similar size, the actual layouts are quite different - the 6 contact pins of the Nokia, have left 6 clear marks on the Virgin SIM card, and it looks to me that they don't line up the same way on the Vodafone SIM.
So, to my question - is there a specfic 2g Vodafone SIM card available, different from this 2g/3g/4g one that I have?
I got my 1100 'late' in the game - not until July 2005. I had a closer inspection of both NZ and UK SIMs and, although the layouts appear to have quite different designs, I can see the 6 contact points of the phone would coincide with the equivalent SIM regions on the new (NZ) SIM. So, probably it's a firmware issue, as you say (given John's earlier info, above).