Problems with iPhone voicemail...

Since upgrading to ios7, my voicemail does not work as well. The phone does not detect my face so my cheek or ear often turns off the message I'm trying to listen to. This does not happen while talking on the phone to a person. Also, if I delete a voicemail, it begins to do an animation, like the message is sinking to the bottom of the list, and then reappears where it was. I can usually delete it but only after tapping delete 2 or 3 times. Is this a known issue? Is there a fix? Thanks!

I would suggest reinstalling iOS 7, sounds like a bit of a corrupt install there.