This is a possibility, based on the limited info:

If the image is shown in the picturebox before you run the form in debug mode, then it apparently has been assigned at design time to the PictureBox1.Image property. When you run the program and assign My.Resources.tropical_island3 to the Picture Box image, it clears the image because My.Resources on your home computer does not have resource like the one at class, or maybe rosource name is spelled incorrectly.