I am using Ext Js 4.0. If you look at the below image capture of the Network tab in IE9, the ext-all.js is loaded twice. There is nothing in the code calling it twice. I use the below lines in the html file to call the extjs script files.
Network_Capture.jpgCode:<script src="extjs/ext-all.js"></script> <link rel="stylesheet" type="text/css" href="extjs/resources/css/ext-all.css" />