Twitter and Facebook icons, not completly clickable

I can't figure this out, basically the icons in the footer for facebook and twitter (but twitter especially), don't seem to be completely clickable, as in only the top half of the icon is a link and can be clicked on.

I get this on my wifes site and this site
http://www.picaflor-azul.com/free-de...erdeen_neutral

I have tested in opera 11, Firefox 4, and chrome (can't test in IE9 as it is broken on my machine).

Its weird there basically seems to be a dead spot (unclickable patch) on each of the icons

on the twitter icon the dead patch starts just below the crossbar on the t and goes down to about 1px above the bottom of the icon?

anyone else seeing this