Can anyone please explain why, in the list of Answers in my User Profile, some entries are highlighted?
Are you sure it's not the browser that is showing you the links you didn't yet visited?
In my user profile, the questions with the title in red are the ones I recently visited. As the different color used for those links depends from the browser, other users could see in red a link you see in black, or vice versa; you can check this looking at my user profile.
I don't remember until when those links are rendered in a different color, though.