Hi, Actually it's a great plugin and i really like it but i have a strange problem with it!
My site score at "http://tools.pingdom.com" is 99 which is great and i have done a lot of work to get that. i installed the plugin and did a test and the score drop down to 76!! Please see the screen shots
Before and After
I did combined and minified all js and css files without any problems but the problem still remains.
Now i deactivate the plugin so the score back to 99.
Would you please help?