Haven't been able to get save() to work.

What I've been trying to test:

saveRegion = Region(79,345,2375,925)
saveRegion:save("test.png")
The progam executes without any errors, but no image is saved. By default the image is supposed to save to the same directory as the script, right?

The more complicated program I'm trying to get working:

imgnum = 0
saveRegion = Region(79,345,2375,925)
while(1) do
   toast(imgnum .. ".png")
   saveRegion:save(tostring(imgnum) .. ".png")
   swipe(Location(100,1200),Location(100,700))
   wait(1)
   imgnum = imgnum + 1
end
I want it to take a picture of the area, scroll, then take a new picture. The program toasts and swipes correctly but no image is saved.

SaveRegion:highlight() does work and highlights the area I expect.