Css problem after updating to 1.3

After i upgrade the plugin to 1.3 i see that the css breaks in my website.

Making little research i found that the default.css file is printed in Header.

How can i deregister this css from theme Functions.php file.

i would like to not load Plugin css at all. I am using my own css styles for this plugin that was implent in to the theme css and there is no reason as i can see to load it in the header if it is from optimization view or from logical view.

So, i would like to get some little help here with deregister the plugins css file from the header.

Thanks guys.