This doesn't happen very often in scientific journals, and when it does, it's always a shock. A paper I wrote about a little while ago, where scientists claimed to have derived sperm from stem cells, has been pulled by the publisher for plagiarism.
The editor of the publishing journal, Stem Cells and Development, decided to retract the paper because the authors had basically copied the first two paragraphs of the paper from another paper which was published in Biology of Reproduction in 2006 (both citations at the end).
According to the editors, other than the first couple paragraphs, the article was fine. So none of the experimental methods, results, or conclusions were flawed or copied. Still, they decided the infraction was too great, and retracted the paper.
The first author on the paper has stayed silent, but according to the official statement from the university, the paper had a different original first author (the second one), who has since left the university and is responsible for the copied text. The paper is being corrected and resubmitted for publication.
As scientists, we are trusted to be ethical in a variety of ways. We're supposed to be unbiased, our experiments have to pass an onslaught of ethical regulations and our character is challenged as often as our research claims. So it's always disappointing when colleagues fall short of the high demands, especially when it comes to something as petty as plagiarism. To me, it's inexcusable - it's hard enough to be taken seriously, conduct successful experiments, and actually produce something that is of value to the rest of the world. To undermine all that work with laziness is just pathetic.
Nayernia, K., Lee, J., Lako, M., Armstrong, L., Herbert, M., Li, M., Engel, W., Elliott, D., Stojkovic, M., Parrington, J., Murdoch, A., Strachan, T., & Zhang, X. (2009). In Vitro Derivation of Human Sperm from Embryonic Stem Cells Stem Cells and Development DOI: 10.1089/scd.2009.0063
Nagano, M. (2006). In Vitro Gamete Derivation from Pluripotent Stem Cells: Progress and Perspective Biology of Reproduction, 76 (4), 546-551 DOI: 10.1095/biolreprod.106.058271