since purchasing my new phone, Samsung Galaxy S4 - the number of calls that drop has grow more than 5 to 1 and signal strength is poor and phone goes into roaming when others around me are not. My other family members are on the sprint network and have no problems. They are using other brand name phones. I previously had a HTC EVO and did not experience this issue. Is there anyone else out there having this issue? I saw other threads about the S3 but not the S4.