Dear jbignert, thank you for your answer. I am using Windows. So, the clipping works better in Mac, but still the clipped formula is hardly readable, since the brakets are not ok.
Thank you for the link, Wern, but I absolutely do not want to export each formula I see first to PDF and then attach that to Evernote (I think that is the idea of that workflow). It is not my idea of a web-clipper and a notetaking programm to require this extra work.
I want to clip Math pages with formulas into Evernote. The formulas are rendered by MathJax http://www.mathjax.org/demos/copy-and-paste/ and just disappear when I clip the article : ( This makes the Evernote completely useless for Math, Physics, Chemistry lectures which are available online and rendered with MathJax. I tried now the webclipper in Chrome and Firefox - both don't work.