Post sidebar widgets duplicated on Category pages

Trying out the Fanwood theme on a new WordPress site.

Have added some widgets (such as Related Posts and Google Maps widget) to page that has been allocated a Category. Everything looks good on the post (i.e the widgets appear OK in the Primary sidebar area).

However, when I click on the category page, the post is listed, but the post’s widgets are also showing on the Category page.

A new post in the same category still leaves the first post’s widgets visible in the category page. Also, adding to or changing the widgets in the first post also results in the same changes in the widgets displayed in the Category.

I’m assuming this isn’t right. Any way to fix it?

Thanks