http://blogs.msdn.com/esosa_en/archive/2007/08/03/how-to-enable-the-sharepoint-reporting-feature-from-the-command-line.aspx
I had a problem with a Sharepoint site recentrly that was not well provisioned and this caused that the audition reports were not displayed on the report site, I was trying to solve the problem with no success for a long time and getting the following error message "The specified web does not contain a reporting metadata list". I was not able to activate the audit feature from the command line either, so , I had to call to my old friend the command line. I used the following command:
stsadm -o activatefeature -name Reporting -url http://[server]/[sitecollection]/ -force
I was able to fix my site with that.
I'm still figuring out what was the situatuion that caused this situation, I think that this site was created with a inadecuate template or is a site that was migrated from a previous Sharepoint version, I will post the reason of this behavior as soon as I find it, in the meantime, this post could help some folks with the same problem.