Can't recover disk space after taking ownership of folder and transfering files.

[Jedd]

I had to hook up an old smaller sized hard drive as a 'slave' in order to transfer 12GB of data inside the "my documents" folder to a larger 'master' drive.
I then had to 'take ownership' of the "my documents" folder on the 'slave' drive to enable this from the 'master' drive.
Transfer of all data was successful enough in time.
I then booted up the PC using the old 'slave' drive on it's own as a singular drive, having altered the jumpers to make it a 'master' drive again, only to find that all of the 12GB of data had disappeared. Obviously something to do with having to take ownership under the shared rights security process.
Not that that is a problem, because it had transfered to my other larger drive successfully - the problem is:
The disk space on the old small drive is still showing that it's nearly full, even though it is now missing 12GB of data.
I've ran searches for the old files just in case they are stored somewhere else, but none were found. I've ran the free up disk space utility, but only recovered a few MB of space.
The reason I ran the transfer in the first place was to free up the space, but I'm no better off than if I had kept all the files on there.
Does anyone know why this may have happened or what I can do to recover the space?Many thanks- Jedd

[plthayer]

Have you tried hooking the drive up as a slave again to see if the files really are still there? If they are delete them, then boot back to the OS on the smaller drive and see what the space shows.