How could a directory transform into a Unix file?

I have an NTFS hard drive which I've been reading/writing to on my iMac using NTFS-3G / Tuxera. The reason that it's NTFS formatted is because it came out of my old PC. Its singular function is the storage of a ton of multimedia -- MP3s mostly, with the occasional video and image files thrown in. I only recently started buying new hard drives but still haven't copied the files over -- mostly because of this problem.

One day, I started noticing that some of my MP3s in iTunes would not play, as they could not be located. When I pulled up Finder to look at the drive, I noticed that the directory where they were all stored had been transformed into a "Unix executable" file. It has the exact same name and modification date as the directory -- a few years ago, which was the last time the main directory was modified, not counting a lot of recent changes to the files inside it -- although its filesize is less than 100K. My drive is still showing the same amount of used/available capacity.

I've scoured several spots online but wasn't able to come up with a similar scenario. Just to reiterate the details:

• NTFS drive being read/written to using NTFS-3G/Tuxera for Mac OS X
• iMac uses 10.6.8 at the time the error first occurred
• Drive shows that its free/used space is the same
• Phantom Unix file has same name and modification date as the directory

Before I break out Data Rescue, which is my next step, I was wondering if there were any other steps I could take, or if my drive is borked and I might as well just reformat it... Any suggestions?

Since NTFS is a proprietary file system developed by Microsoft you can never be certain about whether third party drivers are working properly. Sure, NTFS-3G might be working most of the time, but still they can't deliver such reliable drivers as Microsoft, if only they would put some out. I know this sounds woolly. But when I started on the Mac, I lost about half of my music library to the bad support of NTFS through third party drivers. So to know your data to be safe on a Mac it is warmly recommended to use HFS+ or at least exFAT, if you need to transfer Data between Windows and OS X.

What you can do now:
As long as most of the data is still accessible on the drive, try to get it off the NTFS partition and reformat it to HFS+. It would be for the best to use a Windows machine, hooked up to the iMac via ethernet, to transfer the data off the drive and store it on a HFS+ drive connected to the iMac

Connect the drive to a Windows machine, and then see if the folder works. (This might even work from a Windows VM running in Virtualbox.) If so, copy the folder to a new drive or partition, HFS+ preferably.

I guess the drive is an external HD, and then it shouldn't be too difficult to find someone who has a Windows machine. I think an Ubuntu machine would work as well. It's probably readonly, but that's not a problem if your only goal is to copy data from that disk to another one. (Virtualbox + Ubuntu is free to download, but I don't know if that will solve your problem.)

If you don't have access to a Windows or Ubuntu machine, do not touch the drive, or make an image of the drive, and use the image for testing until all data is safe.