Help with xml gallery

Hi all:

I’ve been struggling with this little gallery for a long while and was hoping someone would give me a little help. I’ve made these galleries a few times before and never had any trouble. I’m thinking that I’ve looked at it too long and its probably something really simple like paths but I’m not seeing it. When I put my images in horizontally, it works fine, however once I put them in a grid, nothing. If anyone could help me, I would really appreciate it. The zipped files are here:

Gallery

Thanks in advance for any help,
Sarah