Does the iPhone 5 require a factory reset to switch from GSM to CDMA

According to StraighTalk, their "resetting" will cause all data to be deleted. It does not make sense to me either.

After I removed the SIM card, the mesage in the upper right corner said "No Service".

Resetting Network Settings made no difference.

When I talked to StraightTalk they made me dial some specifice codes. TFW service showed up in the upper left corner but they could not get it to work.

My mobile number is still valid. When I dial it from a landline, I get my voicemail.

As far as I know, StraightTalk uses the Verizon network for CDMA coverage (even if it says TFW on the phone) but I don't know how they tie into that network.

The problem is that the StraightTalk people seem to work from a script that provides standard answers. They may not know what they are talking about or they they do not want to make the extra effort to resolve this problem.

Either way, I am stuck with these people. If someone can tell me what should be done, I can ask them to take the necessary actions. Otherwise, I may have go through the exercise of making sure that all data has been synced with my Mac and then download all data and apps after StraighTalk had one their thing.

CDMA does not use SIM's.

This from the Internet.

Straight Talk is a prepaid cellphone plan offering both limited and unlimited talk and text options. Sold through stores such as Walmart, Straight Talk uses both Verizon and AT&T networks to provide coverage. Depending on the type of phone purchased, Straight Talk users can have access to the same coverage provided by Verizon's own cellphone plans, but at a lower price.

No, the phone came without a SIM.

When I used at home it worked as a CDMA phone. StraightTalk must have used a Verizon tower because Verizon is the only carrier that covers our neighbourhood.

When I inserted my Vodafone SIM card in Amsterdam it instantly switched to GSM.

Well, I am back again and my iPhone 5 is now working as a CDMA phone.

During my telephone calls with StraigtTalk it became obvious that they knew very little about the iPhone 5.

None of the people I talked too was aware of the fact that the iPhone 5 supports CDMA as wel as GSM.

Eventually, I got hold of a supervisor who told me that StraightTalk did not allow the iPhone to be used with another carrier. The fact that I actually used Vodafone as GSM carrier in Europe, did not change her opinion.

In order to get my phone working again, I did have to do a factory reset and erase all data.

Fortunately, I had done an iPhone backup using iTunes. Restoring all data, apps, songs etc. took about 15 minutes. The only thing I had to do was connect the iPhone to my Powerbook with the USB cable, select the iPhone icon and hit restore.

Since Apple makes it so easy (assuming that you do backups), I have no problem going through the same exercise the next time we travel.

Thanks for all the feedback.