In TouchCopy, select the Files folder on the left-hand side. Then select DCIM. You may see several sub-folders beginning with 100APPLE, then 101APPLE, 102APPLE, etc. That's where my ghost files were. They appeared to be the very first photos and videos I took after purchasing the phone, since they were numbered 0001, 0002, etc. The videos obviously took up the most space. (My guess is that they got cached there automatically the first time I synced the new phone with iTunes, because I wasn't quick enough to turn off Photo syncing in iTunes. After that first sync, I turned off Photo syncing, and the later photos weren't cached. Instead of photo syncing through iTunes, I use Photo Capture on my MacBook Air to download them with more control.) In the trial version of TouchCopy, I could select all of the files, but the Delete Selection button was grayed out. Once I activated the full version of TouchCopy, the Delete button became available, and I deleted the old files in each of those 10xAPPLE sub-folders. I didn't delete the folders themselves, just the files. After that, eject/disconnect your phone safely. Power off your phone, then power it back on and check your usage/free space.
You must have the full version of TouchCopy to delete the files. Rather than pay $25 for the full version, there's an offer to try another piece of software or service. When you sign up for the other trial (I selected stamps.com), you get an authentication code for TouchCopy. You just have to remember to cancel your trial of the other software or service before you get charged for it. Do so at your own risk.
Hope this works for everyone!
