Height of an anchor with image

When I was coding a portfolio with images inside links I have found this interesting issue when height of an anchor is bigger than its image. You can fix it with css: "a {font-size: 0}" (font-size: 0; does not work in Opera 12). "a img { display: block }" should work in all browsers including Opera and IE.
Live example is here: http://hromnik.com/web/anchor-image/