Ever since Sandboxie became free, Help=>Check For Updates always states "The Sandboxie Web site does not report a newer version of Sandboxie."
Do you assume all users like to visit your website and/or forum to catch up?
Well, I do, but everyone I've ever recommended to install Sandoboxie don't.
The only reason they know about new versions is because I notify them about it and then all I can do is hope they listen and bother to fill your download form and actually download, install, etc.
Why doesn't Help=>Check For Updates just do its job?