4s Text Tone Problems

I have a iPhone 4s that's running 6.1 and I have having a couple of issues. 1st issue: When I leave home or work and go from being on Wifi to 3G I am loosing the unlock/lock sounds on the phone. 2nd issue: When on 3G I am not receiving notification sounds when I get a text. If I reboot the phone, it will work correctly for approximately 10 to 15 minutes. Anyone ever had this happen? I've got the sounds turned on at all times.

Thanks in advance,
Scott