[sonyday40]

i dont know if this will help.....but i had the same problem until i did a hard reset. i then applied reg tweaks one by one...and the one that i found that caused this problem was the tweak that applied to in call volume....i used a codyppcincallvolume edit cab and i did the edit myself in the registry and whenever i did anything to mess with the call volume this problem occurred.

so i immediately reversed the edit and now my phone is back to normal.....it picks up all calls immediately. hopes this helps!