In case you didn't see my other post - add the .BR6 extension when saving (or by changing it in the finder). Perhaps an easier way is to create any old file and save it as "default.br6" in the main Bryce folder. This is the file that will load at startup or with the new command. That way when you save a new scene the default.br6 will be auto loaded in the Save dialog. This way I don't forget.