WordPress caption problem

On the Twenty Eleven theme, when captioned images are linked and are hovered over a border appears around them. I am trying to get this to happen in a Twenty Ten child theme and can get the border to appear, however this makes the captioned image move out of the caption to the right.

The code I’m using is http://pastebin.com/UY4ybZJi . So any help on getting the captioned images to stay in the centre?

[posted already here: http://wordpress.org/support/topic/wordpress-caption-images-move-to-right-when-they-have-a-border-and-are-linked?replies=1 – please continue with the original topic and add any neccessary information there]