iphone 3g no signal

[bazzw6]

great so i got a iphone 3g to play with
s/w 3.1.3
b/b 06.15.00
carrier o2 5.0
network o2uk

cydia to jailbreak then ultrasnow 1.2.3 to unlock

problem is its now got a very weak signal so it wont call or txt so decided to uninstall un-jailbreak syill no joy with signal

any help will be greatly rewarded

thanks baz

[fijiman]

Once you install Ultrasn0w you have to reBoot by holding the power button until "slide to power off" appears....power off then power back on. You must reBoot using this method only...signal should be good now...