In Wikipedia's list of Latin phrases, the expression virtus in medio stat is included, with the explanation:
Idiomatically: Good practice lies in the middle path. There is disagreement as to whether "media" or "medio" is correct.
If my deductive reasoning skills have not failed me, the word in question here is medius. In Lewis & Short's definition, I see examples of both in media and in medio, so I'm assuming that Wikipedia's "correct" refers not to rules of grammar but to some "official" origin of the phrase.
Even if that's the case, however, it's not clear to me if there is an actual difference in meaning between the two. So, are both versions grammatically acceptable? If so, are their meanings different, or is it simply a variation in syntax?