I use the RSS Feed block in all of my courses. In Moodle 2.7 (and maybe earlier versions), I noticed that Moodle does not seem to be translating the html special characters correctly (see attached screen shot, where the ampersand character displays as literally &).

It seems to me that I once reported that quotes were not being displayed properly, but I cannot recall. Just found it, MDL-28633, which has been fixed.