I need the capability of storing empty attribute values, but if I choose "Update Item Row" and blank out an attribute value, then press Update, I see the message "The Attribute's value can't be left blank."

Why? It won't even let me do an update with a space character as the attribute value. Is there something in the SimpleDB specification that doesn't allow blank values? I don't see that here:
http://docs.amazonwebservices.com/Amazo ... operGuide/

Thanks for the help!

Thanks for the feedback.. we will fixed it and in next version and you will find, storing of empty attribute values.