When trying to add, delete or change globals I receive the error:

Unable to overwrite file: globals.txt (permission denied). Please set permissions properly and save again.

I tried going to the shell and changing the permission and then I got the same error but in Tools.pm what is going on? what happened?

Make sure that not only the following files are writable by the web user but the directories they reside in as well.

admin/templates/yourtemplateset/globals.txt
admin/templates/yourtemplateset/local/globals.txt

Thanks Aki,

Looks like the web server process that was previously running as a valid userid is now running as nobody.