Buffer 1: Opening a image file without extension in its file name.
Buffer 2: A ASCII text file.
Buffer 3: (generate-new-buffer "கட்டற்ற மென்பொருள்")
Buffer 4: The same image as in buffer one but with file extension in
          the file name.

It looks as if the problem is with the file extension and not the file
itself, I might be wrong: