Problems using an unlocked i855

I ordered an i855, which I received today. I previously owned a i530. I switched the SIM card from the i530 into the i855, and all of my information transferred, but I can't make or receive phone calls. I have a full signal. The phone is basically doing what it would do if no SIM card were in the phone (with the exception that all of my info is in the i855) What is going wrong? How can I solve this problem?

Thanks in advance

---

› See More: Problems using an unlocked i855

hmm...nvm, it works now! I don't know what the problem was before

Sometimes it takes time to switch over and recognize it, If you went from a i530 the sim card will work, but I would reccommend getting a new sim, it will have more memory and it will also make sure that all the features work.