Do any of you guys have your PM open for friends only? I was banned too. It was because she couldn't PM me.
I went to her room, said "hello" and 5 seconds later, she banned me. Same thing as you guys. So I PM'ed her and asked why she banned. I had to add her to my friend list so she could reply me. First she said it was because I wasn't talking and I didn't say hello. Which I did. Then she said I wasn't accepting PM, and that she only talks in PM. Since I didn't PM her when I joined her room and she couldn't PM me, she simply banned me.
By the way, the ban is short. In the next day you should be able to join her room again. Not that I am interested at this point.