Unhappy P999 signal problem on custom ROM, but in the Stock ROM is working, HELP Please!

I have a SIM unlocked LG G2X which I use with TESCO Mobile SIM card (Vodafone Network).
When I flash the stock ROM with NVFlash the mobile network is working!
But the big problem, when I flash a Custom ROM (I tryed these: Tony P ICS 12, Tony P Hackfest JB, Eaglesbood don't boot up and the Hellfire ICS), after it boot up the phone doesn't ask the pin code and no signal at all! :/
Could you help mhow can I fix it? :/