iPhone 4 Call failed after someone hangs up

[genardas]

I'm on an iPhone 4 I upgraded to 4.3 from 4.2.1. I then downgraded from 4.2.1 using snowbreeze custom Ipsw. Every time I am in a call and someone hangs up it says call failed. It doesn't interfere with anything it's just annoying.

[forregand]

I'm on an iPhone 4 I upgraded to 4.3 from 4.2.1. I then downgraded from 4.2.1 using snowbreeze custom Ipsw. Every time I am in a call and someone hangs up it says call failed. It doesn't interfere with anything it's just annoying.

The same here. Downgraded back to 4.2.1 from 4.3, jailbroken with Greenp0ison. Any idea?

[genardas]

nop

[Orby]

nop

If I had to guess, it's probably the iPhone's OS not understanding T-Mobile's signaling protocol for "other person hung up, call is now over" before terminating the voice channel, so the phone only catches the suddenly-dropped call, assuming the call was dropped or otherwise failed due to extraneous circumstances.

It happens on my 4.1 i4 on T-Mo USA too, it annoys me too, but I got nothing. My phone also decides to call voicemail randomly once every so often (usually in the middle of me dialing another number)... also most annoying.

In short, I got nothing. Probably a network-to-phone miscommunication or misunderstanding that can't be rectified on our end.