Problems with HelloGridView tutorial from Android Developer site

Question

Hi, i test this tutorial with the sample images they have and work's ok

but when i put my own images then application crash (stopped unexpectedly)

why? the only i do is to put my own images with the same name than sample images....

for example, i erase sample image "sample_0.jpg" and i put my own image from my harddisk with the same name "sample_0.jpg"

but then the application crash

why?

thanks