Recently I found that when I download a PDF file into a chrome browser window, the Save button (and Ctrl-shift-S) doesn't work on some files. There is no response to either the button or the keyboard shortcut. One way to make it work is to click the Print button, then either print or cancel, then the Save button works correctly. (my chrome PDF viewer is disabled as I have heard that it doesn't have all the functionality of the Adobe plugin yet)