Text overlapping right hand sidebar

Hi,

I am not sure how/why it’s happened but on our blog main page, the text from the blog is overlapping the right hand side bar. See: https://padiproseuropeit.com.

I have replaced the entire CSS stylesheet with another (identical) blog which is not broken, but it’s made no difference so I can only assume this error is linked to another part of wordpress and not the CSS?

If I change the format to “content on the right, sidebar on the left” view then it works OK. When it’s changed back to having the sidebar on the right, it all goes pear shaped again.

Any ideas?

thanks
Danielle