I have Mac OSX 10.6 and drag and drop doesn't work. Have to "add files" the old fashioned way via select buttons and file indication.
I am dragging from iPHOTO in Mac to the folder icons in safari for my Microsoft live.com account. A friend in Russia just tried on a live.ru account, and same problem with her computer using the same mac software.
Security is all standard "off the shelf", out of the box without any add ons.
Kind Regards,
David