Hi,
Just to add a little bit to the inconsistency - I'm not sure I'm getting your description of the behavior correctly, maybe it would be clearer in other words..
As for the security, when dealing with files, you should be also aware of the
Check files permissions setting described at
DevGuide - Files related settingsCheck files permissions - If checked, document permissions are applied to the files.
Should you need any additional details, please feel free to ask.
Regards,
Zdenek