Yeah thats what My 9mth old does as well, Put her on the floor and if no-one around she whinges etc. i think it is more boredom or she is so use to having someone around her every day due to an older sister she wants the attention. She is alot better now though and can entertain herself more. Maybe that the same with your little one too but she has decided to do it alot earlier for some reason

Hope she gets better son for you though.

jen