Tech help needed!!

I have the two following bits of code for two of my sites - to show an image when hovering over a link.

Here's the question! It appears that the image only appears on links that have already been visited ~ is that correct??? Shouldn't it appear on ALL links when hovering?? I haven't noticed that on other sites before, though so I don't really know!

Confused!!

For Jeans:
a:hover {color: #3399ff; background-image: url(http://www.mishmish.org/www/jeanshover.jpg); text-decoration: none;}

For Daily Venting:
a:hover {color: #ff6600; background-image: url(http://www.mishmish.org/www/fairyhover.jpg); text-decoration: none; font-weight:bold}