I keep getting these weird IMs from a different name every night.?

Every night, I get an IM, the same one. from a different name every time. Its the audible under flirts..the fish that says hey y..but the weird thing is, the persons name doesnt show up in the window and the audible doesnt move or make noise. I know that its a different name because it says it on the top of the window but it doesnt show it in the chat part. I get it every night at the same time...Does anyone else have this problem? Does anyone know how I can stop it from happening without ignoring everyone that isnt on my list?