I think i did have a bad case of NTD. I read the symptoms...they match up to exactly what I was seeing at night. I didn't think anything of seeing one or two of my neons up when all the rest were "sleeping" on the bottom. I think the fish received a nibble or two from my angels (which are cichlids, another species that can catch NTD) and they proceeded to drop dead. They lost coloration around the midsection (the neons would lose their blue, the angels' bodies would turn as white as a sheet) within an hour of death. My remaining neons aren't showing signs of the disease. I guess I'll just have to wait it out for a few more weeks before I make any moves towards restocking the tank. I just wish I was a bio major, then I could work on a cure for this disease that bothered me!