After the release of the update to iOS 5.0.1, some Gevey cards remained non-functional due to changes made by Apple in its own operating system. Not all cards were affected, but only some of them, but to solve this problem there is now a beta version of FuriousMod available in Cydia. Considering that we are talking about a beta version, it is good to expect that it will not work 100% correctly with your terminal. The same old basebands remain compatible with Gevey, so if you have baseband 04.11.08 or higher, you will not be able to decode or downgrade.
To install FuriousMod you have to add the Cydia repo http://cydia.myrepospace.com/Squuiid/ and in it you will find the respective package. After installing the tweak, you can go through the normal decoding method done with Gevey and your terminal should display the signal in the upper left. Normally the tweak should only work with some Gevey Ultra cards, but theoretically it is compatible with several models of Gevey cards.
