Ignore that last one, Are you positive that the files are PNG? and if they are have you made sure the Alpha Channel (Transparency) has been removed. If you can also insert your whole text file (So open the material and press ctrl+a then cntrl+c and past it in between the coding that I will list bellow)
Remove the star between the Brackets and the word Code for it to work.
[code*] Insert Code Here![/code*]