Tried just now, from v2.4.1, and the last update downloaded without problem. You can always contact the support email address and request a direct download link.
I've tried to install PDF-ShellTools v2.6.1 from version 2.4.1 but it don't work. I use "check for update" manager with "create local copy". When i click on "install" button, message "Installing ..." appears but nothing happened.