Why do file permissions change by themselves?
Why do the permissions of some files change back to unwritable after I edit them?
For example, I tried to edit template.css but the Template CSS Editor says the file is unwritable, so I found the file in Mac Finder and changed permissions to writable then padlocked the change. This allowed me to edit the file and save the changes but when I reopened the file to edit again the permissions have been changed back to unwritable by Joomla! It's like a game of cat and mouse.
I don't know if it's a template issue or a Mac issue. Does anyone know a solution?
That's Mac's issue. You should change the permission of the templates folder too.
Please let us know if you have any further questions.