We spent a lot of time creating these CSS animated pop-ups that described parts of the product. They looked great, but the client called and said they were "flickering" on her computer. We debugged and could not for the life of us figure out what she meant by flicker. The code was so simple that we couldn't imagine how it could be flickering. It was just a jQuery fadeIn(). It worked fine for us in every browser we tried. So we just gave up. The next day, the client called back and said,"Hey, it looks great. You fixed the flickering. How did you do it?" And our dev replied, "Uh, we set the flicker to 0".