Lava Mobiles — difficult to receive the phone call in lava x 81

Address:

670102

If somebody calls when the screen is turned off, i have to press power button, then touch the phone icon then there will pop up a box displaying three options. First option is touch tone keyboard second option will be return to call in progress and one more option will be there in the list. I have to select one of these two options, then only i can see the information about the caller and receive the call
I can hear the ringing tone
Please give a solution