Iphone get hang if couldn't able to pick up a call with some kind of msg in which none of the displayed option works.....

I Have seriously a very frustrating problem. Now here is the problem when call comes in and for reason if i couldn't pick it up after some time when i check my iphone i get Kind of

image. once i get this image none of the option on the image works. I have switch off my iphone and turn it back again. This is very frustrating. Please help.. One of fren also had this problem long time back he suggest to update my iso to latest which i did. But still i have the same probleM. I tried to see from the setting option to disable this crap but couldn't find it. Please please help me on this how to disable this Kind msg display. Am sick and tried of switching off and turning back my ipho