Setting up an apache based subversion needs a little more work then doing it with a plain or svnserve setup.
My steps are described here and executed on two computers.
Create your repository
# the switch --fs-type fsfs is the default # but I was a little worried of getting the bdb file system svnadmin create --fs-type fsfs demo
Make sure apache is capable of reading the repo and other cannot
# /var/lib/svn is owned by root so let www-data (apache) access the repos dir.
chmod o+rx /var/lib/svn
chmod -R o-rwx demo
chown -R www-data:www-data demo