I have had trouble with browser caching by just left clicking on the button on the downloads page on the web2py.com website. I now make a point of using a right click Save As or whatever your browser provides as the item in the pop up menu to save the file. The first clue the left click didn't actually download a file is the download went too fast but in todays multi-megabit link speeds that may be hard to detect. Also check the VERSION file in the top level web2py directory.
Ron
