When I try to run Firefox 3.6 or 4 beta I get a message saying:

Profile Missing Your Firefox profile cannot be loaded. It may be missing or inaccessible.

I have tried running the profile manger from the command line using:

/Applications/Firefox.app/Contents/MacOS/firefox-bin -ProfileManager

I get the same message in the popup, but I also get:

Error: Access was denied while trying to open files in your profile directory.

I have tried deleting firefox and reinstalling it. I have also tried deleting anything related to Firefox or Mozilla in the ~/Library/Application Support directories, but nothing seems to help. In addition I have run the disk utility to fix any permissions issues.

If I create a new profile or run the command with sudo it works. It seem that that Firefox is trying to put the profile somewhere it doesn't have access to write, but I can't figure out how to change this location or change the permissions. Any help would be greatly appreciated.