Thank you for your answer. I'll definitely include this into the installation script.
These permission issues are mainly caused by the different policies of different webhosting providers.
Such problems are quite hard to reproduce for me.
Wouldn't you mind If I'd sent you different versions and you'll test it, please?
Regarding the advanced settings: what browser do you use? If it's Firefox, please send me an output of Tools -> Error Console -> Errors tab. (press Clear, before you'll access the settings page). Thank you.