It would appear that some of you are not reading your PM's (private messages).
When signed in, you'll see:
"Hey, username, you have X messages, x are new"
In the top right hand corner of your screen. Clicking on the number of messages will take you to your in box.
If you haven't already done so, I would suggest you change your preferences (which can be found above the green bar, on the right had side) so that new messages 'pop up' when you sign in - this will prevent you from missing any new PM's.