Come riportato dal Blog Ufficiale del Dev Team:

Today we released an ultrasn0w update that fixes an issue for those running firmware 3.1.x with the 04.26 baseband. That specific combination resulted in a missing carrier name in the upper left-hand corner of your home screen. Today’s ultrasn0w update from 0.91 to 0.92 fixes that problem (which was an important issue for roaming). You should see the update available if you have http://repo666.ultrasn0w.com as a Cydia source.

Link al post: http://blog.iphone-dev.org/post/238376673