I had exactly the same problem with my Apache. But it works beautifully now, on a Windows machine. Just change all the references in your httpd.conf file to represent 8081 instead of 80.
Specificially
#Listen 12.34.56.78:80
Listen 80
becomes
Listen 8081
That with changing the Virtual path works fine, provided all your links are refernced to the virtual path.
Hope this helps
Kath