If you are reading this page via the Internet, and you would like to install this info/help for the first time in Rubber Dub-Dub, then click on the following link:
Download Rubber Dub-Dub Help File NOW
This installation package contains the file rubber_help.CHM which should be installed in your RD-D program folder in the sub-folder help.
On later occasions, from either the CHM help itself or the Internet, you are advised to go to the link above to check for the latest version of the RD-D program. In general, a new CHM help presupposes that you have this latest version of the RD-D program, so if you prefer to keep your old version, the latest CHM help is not necessarily applicable.