Files in Drop Box disappear after copying across the network.

Hi there,

When I copy a file from my MBP (10.9) to my wife's MB (10.6) using file sharing and the Drop Box, the files take time to copy and I can see the folders get created on her MB, but as soon as the file transfer finishes the files disappear from her computer! I expect to see the files disappear from view on my MBP, but when they finish copying to her MB, they're gone. I have looked everywhere I can think of to find these files- Desktop, Downloads, in the default app they would open with, but nothing- they're gone.

I thought maybe permissions were the problem, so I ran sudo ls in the Drop Box directory, and nothing unusual there.

The strange thing is that this happened with other files last week, so I eventually just gave up and used a USB drive to copy them. Today, the files that I tried to transfer last week are there. But the new files from today are not.

Any insight?