I have this same problem. I have a 2012 Honda CRV. Got my iphone5 in Sept. and was successful in pairing it with my CRV. Everything worked just fine for several weeks. Then just about 3 or 4 wks. ago, I can no longer answer incoming calls from my CRV, but all other functions (like outgoing calls) work properly.
I have deleted my phone pairing twice and repaired anew with the same results. This is so perflexing, as my husband's iphone5 was initially paired when mine was, and he never lost the ability to answer incoming calls.
Can't figure this out! Everything on my bluetooth shows on and active, and the CRV shows my phone is paired and will allow all functions except answering incoming calls.
What should we do?