I wouldn’t make a problem of one low vote, maybe that person was only frustrated because he didn’t get the core of the article. Or in a bad mood. If you don’t want to show this to others I thought as webmaster you do with it what you want. If I cared much I would put somewhere a guideline for rating. E.g. 5 points for the content, 2 for the spell, 2 for the clearness a.s.o. Normally there should be more or less official guidelines. Have you also ever heared about the copyright infringment test? That doesn’t mean necessarily that you copy from other blogs, but it can only be because you accidentally used identically the same combination of three or some more words.
I use the same plugin and still wanted to remark it is already linked at the comment form. Although me I come here for a suggestion also, namely to force things. Mine is a little bit simplier than yours I suppose and hope.
