When the repository directory contains characters that could be encoded by an 
url encoding function procedure (like +), the links doesn't work. For instance, 
I have a respository with the following path:
--> HGROOT/src/main/c++/

All links to this directory (and files under it) encodes the + character, so I 
endup with an URL similiar to this:
http://<host>/paje.cgi?file/3ed29fbed797/src/main/c%2B%2B/

And this returns a 404 error (changing to + characters works btw).