A lot of people are experiencing problems after unlocking their iphones (after an iOS 4.3.1 Jailbreak), where it leaves them without having a signal on their phone.
The affected are listed:
ultrasn0w 1.2 baseband 06.15.00 on iPhone 3GS and 01.59.00 baseband on iPhone 4
Make sure you update to the latest version of ultrasn0w (which has recently been updated to version 1.2.1)
The problem is easily fixed by following the below tutorial:
Step 1: Open Cydia on your iPhone 4 or 3GS
Step 2: Go to Manage->Sources
Step 3: Now tap on “Edit”, then tap on “Add”
Enter the following repo
Now tap on “Add Source”
Step 4: Tap on Done.
Step 5: Tap on Pushfix.info and install
Step 6: After the installation Go to Pushfix.info again. Now scroll down and look for “Ultrasn0w fixer for 4.3.1” Tap on it. Install the package. It will ask you to reboot your device.