Twenty Eleven Showcase template

Hi
I could do with a little help in editing my twenty eleven child theme.

I am using the showcase template for my homepage, managed quite a bit of editing so far, but I have been left with a really irritating white line down the right side of the page which I would like removing, also a white bar before the footer.

Please can someone help, I have spent hours and getting knowhere at:-

Kind Regards
Mark