LockInfo solve your problem with the unlock code (Cydia)

L ockinfo just updated to version 3.0.4.2

This program adds information to lockscreen as calendar events, mail or time. An indispensable part of the jailbreak.

Changes and improvements:

• Fixed an issue where not see the emails (from the Lockscreen) when the device had an unlock code.

The Cydia you can download for $ 7.99 (trial version lasts 14 days).

To install it you have to have Jailbreak.