Wrong MIME type

Works as advertised, but I am receiving a warning for the .css as well as for the .js:

– Resource was interpreted as style-sheet, but transferred as MIME type text/html
– Resource was interpreted as script, but transferred as MIME type text/html

From what I know the browser does ‘try and error’ if either no or the wrong MIME type was specified. It will work, but it’s a waste of time. And since the idea of this plug-in is to speed up things, this could be optimized. Correct me if I am wrong.