ejecting problems with removable media

Hi i have a problem with ejecting my nikon d40 and my cruzer 1g scandisk. I searched and saw that dragging both icons of the "no name" and "u3" to the trash would work but it doesn't. Also i was on a photo shoot today and i was putting pictures onto my macbook and then tried to eject the nikon. After that i had 7mb out of 1g left on my memory card. Why isn't my mac actually ejecting these things?