Please Can Any Body Help Nokia 6630 Problem

i have recently just got a nokia 6630 and when i go to make a call i
says network busy or connection error! but i can still send texts an
if i try to connect to the net it say pocket data not available! so
rang vodafone and they said the network is fine. but every now and the
it will be fine but only for a couple of hours then it does it again!
have only started to get this problem ever since i plugged it upto m
pc and uploaded a couple of themes.
has anybody had this problem and solved it or does anybody know how t
do so?
I have tried the *#7370# reset but that aint worked!
i dont know if i'd need to reflash it and if so what programm i need t
do so or the place to get the correct firmware from!

please can somebody help me

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jasongalliuk