Stock Dialer App

[vomhorizon]

So I am having issues with the dialer app and accidently triggering the speaker phone during a call. At first I thought it was an issue with the proximity sensor taking too long to turn the screen on but when I deliberately try to turn it on using my face it doesn't. It does not appear at the start of a call but all of a sudden during a call my speaker phone will turn on. Any ideas why and how to correct this?