Wait, you tried to put two passcode locks on it, but they layered? If so, you had a software fault with the jailbreak, just another reason why it's a waste of time. If you're not happy with the standard 'Slide to unlock', you can set a four digit pin or a full on normal password like you use for sythe.
How to access
Open Settings
General
Passcode Lock
Turn Passcode On
Enter the passcode (4 digit one) twice
Then you have two choices
Select a simple passcode or not
Keep simple or edit to different
Enjoy the security
Hope I helped, with any problems to do with iPhone's give me a PM, I've been playing around with them for a few years now.