[boost] [filesystem] create directory with wrong permissions

Hi there, when I am creating a directory with boost::filesystem::create_directory() the dir will be created, but the set permissions will not include 'executable' rights. Hance the application is not allowed to traverse into the dir it just created. System is Debian. With normal Unix functions all works well, so I think it must be another reason. Is there anything specific I have to do to ensure "drwx-r--r--" will be set? Greetings... Stephan