I have some Beamer presentations created in LaTeX that use the animate package and which I have played before in Adobe Reader on my Mac. However, these PDF's are no longer playing the animations consistently in Adobe Reader and I don't know why. Sometimes the animations will play, but usually they don't. This is true even of PDFs I download which are supposed to be examples of of using the animate package. Any of the examples on http://www.texample.net/tikz/examples/tag/animations/ for example.