I bought a 1.1.2 and a stealth sim and had some strange problems with the dialer after jailbreak... I installed iWorld (found in the installer app) and it seemed to fix the issues... they weren't the same problems as yours but its worth a try... other than that I'd have to agree with Kingshorty above and do a full restore and jailbreak it again... one more thing... which jailbreaking process are you doing? I did this one made by the Dev Team... just download
this and follow the instructions in the readme file.
Good Luck and I hope everything turns out good for you.