help please

[xiomaraG]

i have a jailbroken iphone 3gs on 3.1 i will like to upgrade to 3.1.2 because i have some problems with my signal in my phone looks like i have no problem all the signal bars are showing but when i recibe a call it doesn't ring it goes right to he voice mail and the phone it's on and i have to turn the phone off and then on in order to fix it.

[sursture]

1 - Restore
2 - Do NOT let iTunes use backed upped settings - Set up as a NEW phone
3 - Use Blackra1n
4 - Install Blacksn0w (Optional: If you need 2 unlock)
5 - Install Cydia
6 - Unlock with Blacksn0w (Optional)
7 - Keep smiling

[xiomaraG]

thank you