Map loading problem.

I am making a map generating program for KAG (a little Game Maker coding test).
The program saves the map as a .png file.
I open them in MS Paint (Windows 7) to add spawnpoints (wich are not generated in the program).
I go to KAG and open the console in Deathmatch and use the /loadbitmap command.
And then the map is generated with only bedrock!

Here is some logged stuff:

[17:56:36] Config file not found ''
[17:56:47] /loadbitmap \ARmaps\GenTest
[17:56:47] *Restarting Map*
[17:56:47] No respawn point found for runner (team 1)
[17:56:47]
[17:56:47] New track added to mixer Sounds/Music/ambient_forrest.ogg
[17:56:47] New track added to mixer Sounds/Music/ambient_cavern.ogg
[17:56:47] New track added to mixer Sounds/Music/ambient_cavern_creatures1.ogg
[17:56:47] New track added to mixer Sounds/Music/ambient_cavern_creatures2.ogg
[17:56:47] New track added to mixer Sounds/Music/ambient_cavern_creatures3.ogg
[17:56:47] New track added to mixer Sounds/Music/ambient_cavern_creatures4.ogg
[17:56:47] New track added to mixer Sounds/Music/ambient_mountain.ogg
[17:56:47] No respawn point found for runner (team 0)
[17:56:50] No respawn point found for runner (team 1)
[17:56:50] No respawn point found for runner (team 0)
[17:56:52] *Match Started*
[17:56:56] Player Henry left the game (players left 1)
[17:56:56] *Restarting Map*

Does it has something to do with the 'Config file not found'?

And here is the .png file i used:


Help plz!


EDIT: I solved it. :)
I needed Paint.NET to save it as a 24bit PNG.