My Contacts application on my unlocked, jailbroked 1.1.1 firmware iPhone suddenly developed a problem and now crashes whenever I try to view a contact or add a new contact. All my contacts also got wiped out! Everything else on the iPhone works fine.

This problem started after I installed a few 3rd party apps, but I am not sure which one actually caused the issue

I don't really want to go through the process of restoring the phone. Any ideas?
I thought of re-installing the MobileAddressBook app, but I don't have a 1.1.1 version. Does anyone know where I can download it?