A colleague of mine has an iPhone 3G, which we have jailbroken and unlocked through Yellowsnow. A week later, he decided to switch carriers (Mobistar to Base, both Belgian operators). The phone didn't recognize the new sim card, so we tried to do the whole unlocking thing from the start. Everything ran according to plan but it seems that the unlock did not have any effect. Is this possible? Should a restore to 2.1 first solve the problem? Any help would be much appreciated!