calls stopped working?anyone?

[Rager02]

ok so earlier my phone completely died out(battery was low)when plugged into charger under bars their was just a circle no bars but text messages and data worked.urgently needing to make a call and not wanting to uninstall 1 by 1 i hard resetted and everything worked fine.so far i installed about every program i had before the reset and all is fine.anyone experience this or have an idea what causes it?
p.s i called sprint to see if everything was fine with my account and it was