Hi all I have both a Vodafone and T-Mobile sim that get pretty much the same signal in my house. Holding the phone 'normally', both sims will drop from 3G to 2G, but then the following difference is apparent; the Vodafone sim will continue to hang onto a fairly decent 2G signal, but the T-Mobile sim will drop to 'searching...' and then 'no service'. Looking into it I see that Vodafone primarily broadcast on the 900mhz frequency for 2G coverage whereas T-Mobile broadcast only on 1800mhz. My slight understanding of this technology is that the lower the frequency, the better the signal penetration. Could it be this that is causing the signal issue for many iPhone owners? I see that in the US AT&T broadcast on the 850mhz and 1900mhz frequencies which mirrors very closely my situation here in the UK. Has anyone got any thoughts on this? Ta! Michael.