OP, I had the same problem on my recently jailbroken iPhone 5 and 3rd gen iPad. As others have suggested, the problem should be resolved by reinstalling Mobile Substrate; I did a full uninstall first, respring (should automatically tell you to), then install, and one more respring (again, should automatically tell you to).
The above remedy only lasts until you do a complete reboot (ie, power off, battery dies...), then you'd have to repeat the process. If you only respring or put your device to sleep, you should be golden. Sent from my iPad.