Today I noticed that when somebody calls me and I chose to ignore or end(if the screen is unlocked) the call or whenever I am in an area with low coverage instead of the usual carrier message " the subscriber you have called is not available right now" or "the subscriber you have called is currently busy", the caller still hears the calling beep beep sound a bit distorted. Has anyone else noticed this? I find this bug very annoying and also it renders the DND feature useless.