Caller is unknown. When I call the number it rings once then goes dead.

I got the same thing. Phone rings once then goes dead but registers as a connected call. It's a number From Belvedere.

4/19/12 at 8:05 pm

also earlier.  I called back, it rang once then went dead.

This is the third day that I have gotten calls from this number, I answer it and it goes dead.

Same thing. Call at 7:51am. I called back and it goes dead after one right. Call from Belvedere, CA

I was also receiving calls from 201-338-6162 several times a day. They called at 6:00 this morning twice. I called back and pressed the button to have my number removed, hoping that would help. Wonder if that just transferred my number to the Belvedere, CA list.