incoming calls not showing when i'm on a call

[dknop]

when i am on the phone and a new call comes in, it give me the tone for an incoming call, but the screen just says "Multiple Calls" and doesn't show the new caller.  There's no way to answer the incoming call (I no longer get the Ignore buttons) and the new call doesn't show in my Missed Calls log.

this is a new problem that just started recently.

Any advice?

I'm on an Iphone 4s version 6.1.2

Thanks,

Doug

[kdjc]

I am having this exact same problem. I sure do wish someone would answer this! I can't find a solution anywhere.