I remember once I had accidently downloaded a widget or whatever its called for the browser toolbar. Think it was because of my wifes facebook, zanga games. Maybe it was the zanga toolbar for the browser or something. Anyway, I was getting blue underlines for all sorts of different words that were links the widget recognized.
To make a longer story shortened, if you have recently added any new toolbar things to your browser that are different then before the problem, you could try and remove them to see if it was the problem. It could be a search toolbar thingy too. It was the issue that I had and it was quickly resolved. Good luck my friend.
-Nuke
P.S. In the browser options I think there is a place to remove those options. Think being the key word.