Updating Lists Won't Work for Me. Ideas?

[Easterflower]

I've tried to create a list, called "In the Coop", so I can add all the types of hens that I currently have. I thought it would be a fun way to keep an up-to-date online inventory. Every time I try to add a hen from the "breeds" list, I get an error message : "There was a problem submitting this to the server. Please try again." Any ideas about why this keeps happening?