I unlocked two 1.1.1 iPhones using jailbreakme.com and everything went fine. Both iPhones could make calls.

Happiness didn't last long. The first time I sync my iPhone with my home PC using iTunes 7.5, the iPhone complete lost their ability to make calls.

First I thought it was an iTunes corruption so I reinstall iTunes and did a revirnizing/restore to the iPhones. With this the iPhones where fine again, but as soon as I sync with iTunes... same issue again. Cannot make calls.

Please any help/advice will be greatly appreciated.