Just to correct MickS, the checkers see it as duplication, but NOT plagiarism. Plagiarism involves copying the work of others or sourcing their ideas. Plagiarism is different from a copyright infringement and differs from duplication as well. Duplication is not encouraged because Google frowns upon it for practical reasons.
HubPages even points out to those alerted that they are not being accused of plagiarism, since it may well be your own work. Rewriting articles or taking a new angle on the same topic may be essential if you want to bring your ideas to HubPages. Just amke sure that it is unique as far as the wording and structure.