It's true. The Help provided with SlingPlayer for Mac 1.0.4 doesn't work with Mac OS X 10.5 Leopard.

When you open the Help, you will see an error telling you that the Help would not open because you don't have an internet connection.

Sorry about the inconvenience. It's been fixed in the latest version of the SlingPlayer for Mac. Go to http://downloads.slingmedia.com and grab yourself a copy of the updated version.