Originally Posted by DXRulz:
“I got the K800i now but i did go into O2 shop and ask them and i told them i want to put my sim (from their free offers) into it and will it get 3G and they said to me that it should do because its an online sim. I guess all i can do is try and if it doesnt then i can either have my number transferred to a 3G sim or use the 3G sim included in the box.”
They have no idea what they are talking about. Being an "online" SIM doesn't make it 3G. On the labels on the free online SIMs, they say "2G Prepay SIM".
Your SIM needs to be replaced in order to use 3G. Luckily, my old Vodafone SIM works with 3G, Vodafone just updated my service and it works - looks like it's different for each network.