DAS:ERROR:Invalid column element.

System

I have a DD config which has two groups: one root group and one non-root group. The config couldn't be simpler but what mystifies me is the error message I'm getting from DAS:

DAS:ERROR:Invalid column element. name-from-field not allowed.

However, I'm not using "name-from-field"... soooo... why would I be getting this error? Has anyone seen this error and could someone suggest something less cryptic as to what it could be?

Dave