A speculative parser tries to optimize loading of content by beeing speculative, sometimes this makes problems. So i had to disable.

Speculative parsing

Both WebKit and Firefox do this optimization. While executing scripts, another thread parses the rest of the document and finds out what other resources need to be loaded from the network and loads them. In this way, resources can be loaded on parallel connections and overall speed is improved. Note: the speculative parser only parses references to external resources like external scripts, style sheets and images: it doesn't modify the DOM tree–that is left to the main parser.
http://www.html5rocks.com/en/tutorials/internals/howbrowserswork/#Speculative_parsing

and Mozilla MDN: https://developer.mozilla.org/en-US/docs/Web/HTML/Optimizing_your_pages_for_speculative_parsing

and Opera:

With speculative parsing, the browser can load external resources such as CSS files and images while JavaScript is being executed. Rendering is still done by the main parser but with downloading being done separately, pages with many resources get a noticeable speed boost.
http://dev.opera.com/blog/opera-11-60-beta-is-out/