Updating IE 9 Plugin

How do I update the IE9 plugin.  I have 9.5 Acrobat Pro and Reader 11 and the plugin is the old version.  It doesn't display PDFs in Skydrive. I get the file doesn't begin with 'PDF' message.  FF works just fine and the files open fine if downloaded and opened.   It's only in IE9 using the plugin that they fail.

Thanks..