Ahhh now I understand, you are using the OLD version that is not even compatible with the newer versions. A LOT has been changed since then, from the ground up and you will find, once you download the latest code, is that it is also much easier as well as more flexible. Since Project Widow has started Eric has been upgrading a lot, going from 0.3.4 to now 0.4.5.
Anyways. CVS is Concurrent Versioning System
The latest CVS of Mosaic is here -
http://ribmosaic.cvs.sourceforge.net/viewvc/ribmosaic/mosaic/All you need to do is to click on mosaic.py, then it will show Revision 1.58 - click on (download) next to it, this is all you need as the python script has all the required Mosaic shaders built in to the script. You can download the rest of the files in the CVS directory but not required for mosaic to run.
I think you will enjoy the latest, it is a far cry from the older version you are using.
I will try to convince Eric to release the code in zip package format soon, after all once Blender 2.50 comes out Mosaic will break and he will need to rebuild it from the ground up.