Sticky post in Page of Posts on Front Page does not take the Background Colour

I’m on hosted WordPress.com using the Under the Influence theme. I can’t find any version numbers revealed anywhere. I’ve just set it up, so I guess I’m using all the latest versions – current at 14 Oct 2011.

My Front Page is set to be a Page of Posts. I have one post set as a Sticky Post, which sticks nicely to the top of the Page of Posts on the Front Page.

I have set a non-white background colour. All the posts and pages take on the non-white site background colour as their own background colour *except* the sticky post at the top of the page of posts on the front page. Just that post has a white background. The other posts in the page of posts have the non-white colour as their background colour.

Am I allowed to show you? It’s binleywoodsparish.wordpress.com

I have checked all the possible settings, and there is nothing to set to change this as far as I can see. Therefore is it a bug?

Thank you for any help you can give.