mkdir, file rw, permission related notes for Fedora 3////
If you are using Fedora 3 and are facing permission problems, better check if SElinux is enabled on ur system. It add an additional layer of security and as a result PHP cant write to the folder eventhough it has 777 permissions. It took me almost a week to deal with this!
If you are not sure google for SElinux or 'disabling SELinux' and it may be the cure! Best of luck!