bought a Vodafone htc 8s phone and works fine on Vodafone and 2 degrees networks. Now want to use with a Telecom sim card as well but it won't detect Telecom network.  Have picked NZ and Telecom in connection setup but when scanning for networks it does not find Telecom network.  The 8s is supposed to be able to use GSM850/900/1800/1900 and HSPA/WCDMA 900/2100 so I should be able to swap between networks when swapping sim cards out.  Vodafone support assured me this could be done and I didn't want a separate phone for each network.
Does anyone know how to resolve this?
Thanks in advance.