"a href" around an HTML table will not work (in some browsers)

I have no idea why this is happening, but take a look at this page:

The wide banner at the top of the page (in the center horizontally) has a link around it (take a look at the source), but for some reason, it is not always clickable.

It does not work in Linux FireFox 3.6.6, but it does work in Linux Chrome.

Is this a common problem? How would I go about fixing this?