yahoo links not changing color?

[jimnyc]

I do a Yahoo search, then click on a site to visit. Normally, when I go back to Yahoo later, and do the same search, the site is listed as visited (it turns from blue to purple in my browser Firefox 27.0.1). Now, when I go back and do the same search, the site remains blue, as if I never visited. This is the same for any page I visit. I opened Internet Explorer and the same problem appears.

Yes, I am logged in. I have tried deleting cookies & temp files, no luck.

Any ideas?