Make sure the programming is correct on the phone. MDN, MSID, and Home SID. These are all programming numbers that work on Sprint's network. Do you have Sprint at the moment? Helio has some great devices.
Right now I have the old IDEN Nextel. I know some people who have Sprint and can't wait to get rid of it because the service is horrible here. That's why I was hoping Helio would work out a deal with Verizon.