I have a quick question regarding for 2g iphone about network provider problem.

iPhone Generation : 2G
Current Firmware : v2.1
iTunes Version : 8.0
Jailbreaking software : quickpwn
Problem Encountered : the iphone is running well under maxis and digi, but not compatible with celcom..
Steps Had Taken (list down) : had check with phone settings, the phone can detect the sim card and show the sim card phone number, caller id is turned on.. just cant receive any signal from service provider, cant even make call or sms.
Problem Screenshot (if any) : n/a now
Other Info / Remark : the celcom sim card chip is bigger one, do i need to replace a new sim card from service center?

I mean the size of the golden plated chip on the sim card