I was trying to look at my very own site, which you see here, before I did the upgrade to Drupal 5.6. I got “access denied” errors on the home page!
After a little bit of trial and error, where I discovered that:
- Firefox showed me the page just fine
- I could log in and front page worked
- there are several threads about this at Drupal.org
… I took one of the steps suggested on Drupal.org, and deleted the browser cookies related to the site. I quit Safari, relaunched it, connected, and it worked again. This was the first time I’d seen this with Drupal and I hope it’s not that common.