You know what usually happens during the first few weeks after the initial launch of an OS: bugs. Yes, bugs happen to all newly-released applications. In OS X Leopard's case, a somewhat-serious bug has been found, and it results in files getting erased into virtual limbo.

So what is this bug? Eagle-eyed Leopard user Tom Karpik relates how an entire directory disappeared while moving files in Leopard, using Samba.

Without getting too techie, here's how the bug is triggered: while moving files - especially large files or volumes - if the destination volume disappears in the middle of moving operation the data will disappear. For example, if the mounted drive in Samba goes offline while you're moving files to that drive, the files that are being moved will get deleted.

Karpik made a helpful and informative demonstration of how this bug works in his blog, so it's good to check it out for your future reference.

Check out a comprehensive explanation how and why the bug works in the Via link!