With iTunes on Windows (which mandates QuickTime as well) IE7 can't open .png image URLs (e.g. http://www.example.dom/image.png).  When you navigate to such an URL two popups show in succession:


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Plugin Error
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An error occurred inside a plug-in contained on this page.
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OK   
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Plugin Error
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The plugin did not initialize properly.
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OK   
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Then click on the Quicktime icon that is a placeholder for the image, and:



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Plugin Error
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The plugin was found, but an error in the plugin has occurred.
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OK   
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