Cannot place calls using Local Prepaid SIM on Sprint 8830...

I am currently using my Tour out here in Taipei, which by the way is pretty fast on their 3G system.

I also brought my 8830WE with me, and purchased a local prepaid SIM card. The phone registers the SIM just fine, and I have full signal on their network while displaying the carrier name (TW Mobile). However, I cannot place or receive calls. When hitting the SND key, the phone will just display "Calling..." and not actually connect the call.

I asked the tech at the local cell phone shop (who also carries BB's), and they told me that I need to change my MRL? On the phone display, my 8830 is still showing my local US number, and NOT the local SIM card's number. Should this matter?

Thanks in advanced.

Jeff

Just for more background

Is the 8830WE an AT&T phone? If not, might the sim card slot be locked. With Verizon, I had to unlock the phone by calling their global support and getting codes from them.

What's in the Tour?

Ah, I see you are sprint and AT&T

8830WE is the CDMA/GSM "World Phone" from Sprint. It does not have a subsidy lock, and I am able to pickup the local carrier without a problem (TWMobile). The problem is that the phone's MRL was originally programmed under Sprint with my US number (+1 xxx-xxx-xxxx), so with the local SIM card (I am here in Taipei City, Taiwan), the phone thinks I am either roaming, or on a foreign network--even though it should work as a local phone. So when I try placing calls, the call will not connect and just try connecting until it times out and displays "Call Failed".

I browsed some forums and they said to download QXDM so I can acquire my MRL information so that I can reprogram the phone with my local number.

This is just a *guess*, but I'm going to say it should NOT matter. I know this isn't EXaCTLY apple to apples, however, I use my Storm on both Verizon and T-Mobile. When I'm using the phone with the T-Mobile SIM, it shows my Verizon number. It works fine.

Just a guess though, I'm no expert.