The solution is to enter the slash before the path name in the Home URL field of the virtual host or virtual server document.
eg
for http://adfos.com put in "/af/adfos.nsf" instead of "af/adfos.nsf"
or for
http://www.adfos.com put in "/af/adfos.nsf" instead of "ad/adfos.nsf"
this has the added bonus of allowing # marks through into the domain name so you can neatly have different access points into the website:
eg:
http://www.notesninjas.com/#Sales and http://www.notesninjas.com/#DomainPaths
These can be processed by javascript on the page loader.