Sounds like you should not use the Musica theme.
I´m not shure what you mean with "switch to default 2011/2012 theme" ,-
He means that you should activate one of the two themes that comes in every up to date installation of WordPress: Twenty Eleven or Twenty Twelve.
Those are the themes we switch to to see if the problem that a person is having is related to their theme or theme customization.
So far, you seem to be saying that you have this problem with the "Musica" theme.