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.

Was this done? I still get the error. I'm now using version 2009.02.07.01, which I downloaded about 5 minutes ago (to test whether I can leave attribute values blank).

Yes.. We have done. You will get this change in new version of SDB Explorer that is about to release soon. We will let you know.

Thanks