Never mind.. hada brain **** when i wrote that last reply.. i was thinking about sampling instructions.
In the COA profile you are saynig they are required? Then how are you seeing the COA? The COA shouldn't even print if a required characteristic is missing?
So if that condition is being meet, the COA program might actually be getting the data. It might be some logic in the SAPscript.
It's hard to help since you have custom program for QC21. One of the reasons I highly recommend you don't put in a custom program for COA's. I have a blog here in SCN about it. You might want to read it. Not that it will help you much right now with this specific issue now.
An ABAP'er in debug might be your best bet to figure it out.
Craig