Scroll box trouble with Internet Explorer

Hello,
When I see my site on Internet Explorer, the Agama scroll box is under the IE scroll box and none of them work properly. There is no trouble with google chrome and mozilla firefox, only with IE.
Is there anybody that know how I can fix this ?
Do you think I have to change my theme ?
Please, help me ??
Valérie, revedelignes.com.

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