norway1456, Bluefire needs the Backgrounder hack in order to work on a jailbroken iOS device.
It's linked elsewhere in this thread (multiple times), but the short story goes something like:
- Download Backgrounder (make sure you get the right one for your iOS version -- the 2.x version in Cydia is for iOS 2.x and should not be used on iOS 3.x or 4.x)
- Open the Backgrounder app and select Overrides
- Add a new override for BlueFire and set backgrounding method to Off.
Bluefire should now work without crashing your jailbroken iOS device.