"Unsupported Marker Type"

Using the vtour droplet, I included a flat .jpeg map file with my pano scenes and got an immediate "unsupported marker type" error related to the flat map file. When I looked on the web, I found a suggestion about using Windows "Folder Options" to uncheck "hide extensions for known file types" box. I did this, but quickly noticed that every file on my computer that previously showed a .jpeg extension now shows a .jpg extension. I saw something strange flash with the photoshop.exe file just before this change occurred. Before the mass file extension change occurred in the computer, my initial attempt to load the .jpeg map file into the vtour droplet worked....kind of, but in viewing the tour,it would show the flat map file only briefly when transitioning from map thumbnail to the ensuing pano thumbail and then back. Otherwise, it just showed the Black KRpano "loading" screen when the map thumb was clicked . Does anyone have any ideas?

Thanks in advance, Reggie

OK, the mystery of the spontaneous file type change has not gone away, but on the web I found a workaround that involves opening the parent .jpeg file in Paint and saving it as a copy from Paint. Photoshop will now open the file, allow me to edit it and save it as, now, a .jpg file. The KRPano vtour droplet will now accept the file. I am nonetheless disturbed by this unnecessary additional step in my workflow that didn't present itself until today. Can anyone explain why the .jpeg/.jpg marker type changed virtually right in front of my eyes while I was working?

Thank you again in advance, Reggie.