How to prevent iframes from overlapping with fixed content?

I have a fixed bar on the top of my site, when I scroll all "like" buttons and similar overlap with it.

How can I prevent it from happening?

You can see what my problem 开发者_JAVA百科is here:

http://chusmix.com/chusmix/?ciudad=Buenos%20Aires

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I'm assuming the fixed bar is floated, have you tried changing the z-index of the bar to something like 9999?