Hi
Edit: Assuming the Asus is Network unlocked?
It might be as simple as a little bit more movement in the Sim tray. Obviously the Sim is operating, so perhaps extract the Sim from the Asus, power cycle the phone minus the Sim, reinsert Sim and see if it's recognised...
If that fails, as first mentioned-the Sim might have a little bit too much room in the tray, and connections might not be made, so a little padding of the Sim might be required, however, try the Power cycle first and post back if problem persists.
