Tmobile Dropped Calls and Losing Service

[rudypoochris]

I have a pair of pentaband 920s, one is a developer device and the others a standard unlocked Rogers. Both are on the latest Rogers ROM. I frequently lose signal on both devices. Will go from 4-5 bars to no bars or the icon with an X through the service. This will cause calls to randomly drop and internet to stop working. After 5-10 seconds the service comes back. Sometimes the phone is stuck in edge. I have tried setting the carrier manually in the cellular settings and it makes no difference. Any thoughts? Thanks.