No call notification

I've been trying to figure this out for a couple days now, and it's really getting annoying, as I'm missing all my calls. When I have an incoming call, I get no notification. There's no ringing, nothing pops up on the screen, etc. I have flashed different rom versions, with no luck. Originally when the problem started I was running 20270. Since I've upgraded to 20273, with no change. Any input on this would be greatly appreciated. When I flashed 20273 I did a minimal install, no bells and whistles, no extra apps, pretty much nothing but a couple ringtones, HTC audio manager, and that's about it. Thanks for input.