A peculiar issue with css links

[Viamnding]

I have this CSS code for links on my site:\[code\]a { text-decoration:none; color:#2B5384; }a:hover { color:#F90; }a:visited { color:#2B5384; }\[/code\]It works fine if the link looks like that: \[code\]<a href="http://stackoverflow.com/questions/14547876/mypage.html">My page</a>\[/code\] - the color of the link is dark blue, on hover it changes to orange and the underline appears.However, if I link to external website, for example \[code\]<a href="http://www.facebook.com/mypage">My page</a>\[/code\] - on hover the link doesn't change the color and no underline appears. It works if I change the URL to have the .html extension - \[code\]<a href="http://www.facebook.com/mypage.html">My page</a>\[/code\], but, obviously, there's no such page.Why is it happening and how can that be fixed?