Why is content disapearing in IE 7,6?

There is a link to the page, that has this problem: http://www.klds.cz/aktuality

This is how it looks in every modern browser:

And here is how it looks in IE开发者_JAVA百科7 and lower:

Enyone knows what's going on? Thanks.

Your clears need to be changed. I've had a LOT more cross browser success by using overflow: auto; than any clears. Try the below, it worked in my test.

Remove .clearer by commenting it out.

.clearer {
    /*CLEAR: both*/
}

Add a new entry to main.css to allow it to overflow properly

.news_main  .item {
    overflow: auto;
}

I tested a copy of your site with the changes on IE7 and that resolved it.