What http server your running? Apache? Can you get to other areas of the server? Say just / ? What permissions do you have /home/zach? Trying setting it to 711. If you are using Apache then check your httpd.conf for the following lines:
<IfModule mod_userdir.c>
UserDir public_html
</IfModule>
this defines public_html as the directory to look in when you access a ~username URL. You might also wanna try accessing
http://localhost/... but I don't believe this will make a difference.
Cheers!
Jamie...