Fuzzyband just announced on their Twitter page that version 4.1 is out on Cydia. It confirms that it will downgrade baseband version 5.14.02 to 5.13.04 for Ultrasn0w.
However, this only works for bootloader version 5.08.
How to downgrade your baseband:
1. Launch Cydia from your springboard, and go to systems under section tab.
2. Press to select 3G Fuzzyband Downgrader from the list of packages and click on install.
3. After installation is completed successfully return to Cydia and press home button and launch Fuzzyband.
4. A message will be displayed if your bootloader is not supported, If you have the 5.08 bootloader you will be able to downgrade from baseband 05.14.02. Press the Downgrade button to begin downgrading your baseband.
5. Once the downgrade has completed successfully you will be displayed a Done! message saying, “I Haz Downgrade!”
Did this work for you, leave your comments below?
Do a hardware downgrade and unlock your iPhone! Read here.