Just make sure you set these properties:
gallery1.FilesPath = "~/DotNetGallery_files"
gallery1.FolderPath = "~/CustomerImages/samplefolder"
in vb, or in the config file you can set these. Here I am doing it in vb. If these are not specified correctly nothing shows up and there is no error. Totally annoying I agree. I just figured this out.
Josh