Internet Explorer 9 - double click on buttons? why?

Internet Explorer 9 - double click on buttons? why?

Hello,

I have strange problem with IE9. When I want click on "NEW" button for new product. Nothink happend. When I check some products and click on DELETE, nothink happend.

I try click on this buttons 2 times, like double click - then this is working correctly. Why this need double click?

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