Problem using turbo card in Cyprus with CYTA

[arfawkes]

Hi, I bought a cracked iphone in UK which I was told would 'work' with any provider if I bought a turbo sim card. I found the apprpriate card in Hong Kong, fitted it in the sim case along with a CYTA sim card. Initially it worked OK but as soon as I moved away from home by more tahn a couple of miles it failed with the advice 'No signal'. Everytime I tried gte the iphone to find the service it was unable until I put the CYTA sim into another phone and when the 'different' mobile had connected to the provider, I could then reinsert it into the iphone and it would work again until I moved acouple of miles. On one occasion it allowed me go to the next town and worked there for 2 hours then failed.
Does anyone have any idea what might be happening? I updated the software (after all these failures), on 30th. Jan 2009, but the failure has remained exactly the same.
ATB,
Andrew