Hacking MenuPatcher Background

[.:Niki:.]

I want to change the background, but i have a problem.
I have download the source, i have delete the file background in /data/background, i have create a "background.png" file, i have rename the file in "background" but when i load the homebrew the background its not change,
What is the problem?

Excuse me for the use of the verb (I go at 3° Secondary School)