Strange issue whilst calling a friend!

[Grassmasta]

So, it would seem as though every time I call a friend of mine, his iPhone doesn't ring, nor will it let him answer or decline the call (we figured out you can just press the volume down button and it will answer). But after playing with it (tried to change the ring tone, do the earphone jack trick, make sure his ring volume was up, called from other phones, even restored), I'm more awed than a cave men first seeing fire.

I thought, "surely after a restore this device will function properly." But it seems to have only resulted in epic failure.

Any ideas?

Edit: Oh yea, hes also running an unjailbroken, regular, boring, everyone and their grandmother owns one, stock iPhone (no "accidental" blacklisting...lol, I had to call him some names cause i thought he was blacklisting me for kicks.)

[itsjustlenny]

im having the same issue. my friend just got an iphone and everytime he calls me i cant answer it. i have to miss the call and then call him back. its strange. i have other friends and my wife who own iphone and it never happens when they call me. its just this 1 friend's fone that i cant answer his calls. i have no idea why.im stumped