Extracting with output sets

We're having a bit of trouble using an output set in an extraction. We want to include decoys, but they are not being included when we use this output set. I've seen before decoys not be included when there are columns in the output set that are not included in the decoy system table, so as a test I took columns out of the extraction one at a time. To my surprise I found that the offending columns were Customer_fname and Customer_lname. Salutation1 works fine, but we would like our file to split the first and last names. 

Has anyone seen this before? Any suggestions would be great.

Thanks,

Brian