Comment 6 for bug 776801

Without observing any activity here, I decided to investigate this bug myself. I found out that it happens because jQuery expects the AJAX response to be XML and fails to parse it as XML. I tried fixing this by adding an appropriate argument to the relevant $.post() call; that is, I changed line 77 in js/sideBar.js to

  }, "text");

Which fixed this particular error. However, those errors keep appearing all around, probably because of similar things in other requests.

I suppose this should be helpful.