Haven’t seen much from the iPhone Dev Team lately but they released an update to their ultrasn0w product that fixes an issue for those running firmware 3.1.x with the 04.26 baseband. Apparently, that specific combination resulted in a missing carrier name in the upper left hand corner of your home screen (Springboard).

Ultrasn0w update from 0.91 to 0.92 fixes that problem, which was important for roaming on your iPhone. You should see that update live now if you have http://repo666.ultrasn0w.com as a Cydia source. If not and you want/need this update then you should definitely add it by going to Cydia -> Manage -> Sources -> Edit -> Add and input the above URL.

- source: blog.iphone-dev.org