Dead Links Tied To Area On Page?

My website is http://spacetalknow.org/

The problem is that there is a space at the upper right hand area of the right-most column, which will not allow links (various badges) to be active. It’s very strange, but if I add spaces such that the links are moved further down the column, the links activate. How/why could there be such a dead space?

I’m placing my badges there via a widget called PHP Code. It’s a tool that allows you to drop in PHP and – in my case – HTML code. I don’t believe that the problem lies with this widget, because I’ve used other widgets to do the same task, and the result is the same: dead links.

I’m at a loss as to why I have to slide my links down the page to get them to activate.