HTML Links problem

When I click on the link every works perfect. And when I click on the left arrow to go back everything goes perfect. But if I click on my index.html instead of previous page, the links doesn’t work anymore. The underline doesn’t show up and I can’t click it. Can you help me?

[code=html].left-topic-title a:link
{
color: #FFFFFF;
text-decoration: none;
}

.left-topic-title a:visited
{
text-decoration: none;
color: #FFFFFF;
}

.left-topic-title a:hover
{
text-decoration: underline;
color: #FFFFFF;
}

.left-topic-title a:active
{
text-decoration: underline;
color: #FFFFFF;
}[/code]

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