[RhacRick]

That's so coincidental, because I was just about to post a similar issue.
I don't really know when this started happening for me, but sometime after I installed the "official" leaked rom, tomtom, google maps, a stopwatch program, and various other programs that should have nothing to do with system sounds, my ringtones stopped playing.
I will still receive calls, and the phone will still vibrate, but it will not audibly ring. If I put my ear up to the speaker, I can hear a slight hiss, like when a speaker is receiving power and is turned up, but no sounds are being played.
Is this similar to your issue? If so, I need help with it, too. If not, sorry for the hijack and I'll start my own thread.