I had several virtual hosts working perfectly on my iMac under snow leopard (10.6.8). I upgraded to Lion(10.7). I had saved my httpd.conf under a different name and simply renamed the new Lion httpd.conf and reamed my saved custom file to httpd.conf. I restarted apache.
Now when I point my browser at the proper web address, I get a 403 error:
Forbidden
You don't have permission to access {resource name} on this server.
I have a custom name for the web site which is how the virtual site is accessed, the name is defined in my hosts file and I verified that the name resolves to the correct ip address (It seems hosts entries under Lion are now case sensitive).
I even went so far as to change the name of the apache user to my user account and still get the error (my acct owns the html files that the web server is serving).
I have verified that apache is using the httpd.conf file that I expect it to use.
Best Answer
Things I would check:
Options Index
)If you would update the question with any relevant error_log entries, that can help diagnose the issue.