Files apparently not actually deleted from HD

Hi,

When I try to delete files from peripherals like my removable HD or USB key, they get deleted on screen yet no space gets freed up on the device that they were supposedly remove from. I don't know if this makes sense and I'd appreciate any help. Thank you.

Nick

Did you empty the trash while they were mounted?
Each one has it's own .trashes folder even though you only see one Trash.
Dragging something to the trash doesn't remove it from the drive until you empty it.