I have a 512 mb SanDisk cruzer mini flash memory stick. I've been using it to transfer files from a PC to Mac, but I'm having trouble deleting files on the stick from the Mac. I drag the file I want to delete from the stick to the Trash and assumed that it was gone, but when I plug the stick into the PC, all the files that I thought I deleted are in a folder called "trash" that was invisible viewing on the Mac. How do I properly delete files from the memory stick while I use it on my Mac?