snow leopard ate my apache config files
Being a Mac Geek, I purchased Snow Leopard and did the upgrade this past Sunday night. I did not get a chance to make sure everything worked after the upgrade, but I assumed it did.
Today, however, I tried to start up one of my ColdFusion instances and then went to a site. I got the big "Forbidden You don't have permission to access / on this server." error message in my browser. After doing some digging and working with Phil, our Mac god, we found that the httpd.conf file was modified. Around line 173 of that file, there is a block of code that was changed to this:
Options FollowSymLinks
AllowOverride None
Order deny,allow
Deny from all
</Directory>
That last line is the key. I changed "Deny" to "Allow" (case sensitive without the quotes). Then I restarted Apache.
Once that was done, I got the "Not Found The requested URL / was not found on this server." error. We used named servers in Apache. Well, I looked in the httpd-vhosts.conf file, and it has wiped out my entire file! This is where I had all of my servers set up. I had to find an old copy and get one from a coworker (thanks Asha!) to get back up and running.
So, before you upgrade to Leopard, make sure to back up your httpd.conf file and any of the files in the apache2/extra directory!
I did find that in the apache2/users directory there was a file entitled myusername.conf which has what was the original of the code posted above. So the upgrade knew enough to save this off, just not the other stuff.

Thanks for the tip (in case it happens to others). When I upgraded last week I did make sure to backup those files first just in case (because I've seen them wiped out before during an OS X upgrade when Apache was upgraded from 1.x to 2.x - luckily I was warned by someone like yourself before I did the OS upgrade).
Thanks for this post, I was adding websites a lot differently in Tiger.