U can't just assume that it is official Singapore unit, coz it might be a locked US unit that they sell in singapore...and there is a difference in the cause based on the description of that problem...

If it is really official sngapore unit, the possibilities are:
1. He/she ticked activate the iPhone button while jailbreaking
2. The sim card used is too old
3. The iPhone is faulty

This post has been edited by psyeo: Nov 5 2008, 12:22 PM