Are you saying that you have to enter http://10.0.0.1/mwiki1.7.1
to get to the page, but you want to just enter http://10.0.0.1
If so then you just need to change your DocumentRoot
in /etc/apache2/sites-enabled/<yoursitename> (perhaps default)
find the reference to DocumentRoot and change it to
The reload apache
If I've misunderstood your problem please give more details including the full urls that you are entering / wanting to be able to use.