Strange Message when Logging On

I get the following message when I log on:

"You haven't posted a single message on our board. This puts you at risk of losing your account. Why not start by introducing yourself.
Welcome back! You havent't logged in for more than a month. We missed you, where have you been?"

This is not correct. I logged on yesterday and posted some pics in 'Groups'.

What's up?

These messages will clear if you clear your cookies, or log out and then log in again.

OK