Link color problem in MS Internet Explorer

Occasionally, and more often lately, and especially after I've re-started my PC it seems, I have a major problem with the colors of the links when using Microsoft Internet Explorer 6.0 as my web-browser. I have the color of all unvisited links set to be red, and the color of all previously visited links set to be blue. Now the problem is that sometimes all the blue, previously-visited links are "refreshed" such that they all become red, unvisited links. What causes this problem, and what can be done about it to prevent it from happening again? Any efforts to help will be appreciated - thanks.

 

Clearing the Browser's history could do that...

 

Thanks, but I've never cleared the history, had set it to last as long as 31 days (a full month), and have recently changed it to last as long as 100 days.

 

I have tried every other way to make the changes disappear and the only thing that made it disappear was 'Clearing the Browser History', may be you are not doing it yourself but a program that you have installed? I am not sure what else to say but I have not encounter the same problem on my browser without clearing the history.