Common problem using turbosim.
At times no service - just reset network. From Setting-General- Reset.
Or do not off the phone. Once the phone shut off it will take some time to search network then no sim will appear.
Certain version turbosim will support Celcom but not necessary will work on other telco.
I have changed my turbosim, 3X.

1st - no service can last for 4/5 hours
2nd- no 3g signal
3rd- so far ok

I guess it better for you guys to open a new thread instead of posting your price in the section.

Lets keep this section strictly US model and no other.

You are right.
My unit was done this way.
No way US set came unlock.
Turbosim was inside the unit.

It will not brick the phone.
Just remove sim card and upgrade FW.
I done that from 2.0.2 to 2.1 no problem.

Anyway after 2.1 still have to JB.
For original unlock sets still have to JB.
The only troublesome just remove local sim to upgrade.

Upgrade as usual via itunes.
Or you may want to wait for the 2.2_restore.ipsw to release then only you upgrade and restore.

Just remember to remove local simcard before any upgrade of FW.

Once Apple release any future FW updates.
Every JB phone in the planet will be factory restore mode whether official unlock or lock.
All your apps downloaded by Cydia besides app store will be wipe out.

So even official unlock will not be spared.
Official unlock still have to JB at the end of the day in order to load Cydia/Installer.
Have to repeat the process again to download apps via Cydia/Installer.

This thread is US 3G so its locked to ATT.
You will get unsupported sim warning.

Once a phone is locked.
Any JB method will not change the status of the phone- its locked anyway.
Unlocking and locked are 2 different issue than JB.

For my locked phone I can be able to sync no problem without removing sim card.
Only upgrading need to remove local sim card.

I just pwn to 2.2 with turbosim attached.
No problem encounter. Can call in/out everything working fine as per post 2.1.

For those of you using turbosim, I was being told do not upgrade to 2.2 as the current turbosim does not support the latest firmware on 2.2.

A seller told me that Quickpwn not successful- after 2.2 the phone will encounter no service. They are waiting for the new turbosim which can support the latest firmware.

The latest 2.2 will break your current turbosim.
Surprisingly I survived after 2.2 with turbosim but I am using pwnage tool.
Now I wonder pwnage tool will be a better option than quickpwn.

Thanks. Good thread.