Hot damn, that was it! I went to the devices tree and looked at the two disks showing up. One was the new media drive I had just purchased and installed, the other was the drive that held the core. I thought that was the way it was supposed to be. I deleted the device for core's hard drive, deleted the 3000 files in mediapics, then opened a terminal and reformed the video database as shown above. After restart things were back to normal. I also noticed that the hard drive I deleted was set to "public" instead of "use LMCE file structure". That always seems to cause trouble as well - don't really know why the public option even exists.
Until this point, I had been trying to fix this through media synch.