Actually, since making my post I think it is caused by my micro SD card getting corrupted. I don't know if it is caused by Cura?
I have been saving the G-code file directly from Cura to my microSD, then ejecting in cura from the little popup at the bottom of the screen. I noticed after doing so, then reinserting my MicroSD and trying to access the files in Windows, it would freeze up and crash windows explorer. This was repeatable. This might explain the strange behavior of my printer.
If I save the G-code file to my hard drive then copy the file to the microSD, and eject from the windows tray icon, it seems to work fine. I just started an 8 hour print and so far so good, but we'll see.
When I get octoprint set up I don't think I will have to worry about this.