Who is "#1" and what are they sending me?

Over the course of the past week I have received 4 or 5 offline IMs from "#1" with the following message:

"You have a message from #1 waiting for you in Second Life. Log in to see it."

I've not seen anything in particular when I log on -- no IMs, no notes, no objects... but it is starting to bug me. Who is this "#1", why are they communicating with me, and how do I make them stop?

That's very odd, I believe that must be a bug. A very annoying one! Please file a bug report and save the RT number you receive in email and send it to me at [email]Blue@lindenlab.com[/email] and I'll get that to the QA team to check out.