i have the same problem:
when calling this URL /wp-content/plugins/wp-minify/cache/95def3050d912522de9189a049ef208a.js?m=1393195456
i get: "Uncaught SyntaxError: Unexpected token <"
If i try to call the URL in my Browser i get:
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<title>401 Authorization Required</title>
<p>This server could not verify that you
are authorized to access the document
requested. Either you supplied the wrong
credentials (e.g., bad password), or your
browser doesn't understand how to supply
the credentials required.</p>
<address>Apache Server at p Port 80</address>
For the CSS file its the same.
I have checked "Use "pretty" URL". If i uncheck this i get an 400 Bad request.
FirePHP says: /wordpress\/\/cdnjs.cloudflare.com\/ajax\/libs\/jquery-easing\/1.3\/jquery.easing.min.js\" failed realpath()"]|
Hopefully you can fix it. It is a great Plugin.