Files will not move to Trash.

I've recently been deleting images to make room on my Startup Disk. I had just about finished up when all of a sudden the folder went white, and said I had 0 files in that folder. After a couple seconds all the images I had deleted popped back into the folder, and a message appeared saying the Startup Disk was almost full. The weird thing is all the images were still in the trash, but they were also back in the folder. And now I can't delete any of the pictures from the folder. They'll move to the Trash, but they won't remove themselves from the folder. Any help would be greatly appreciated.