Update of Raw data? using 9.2

The columns orig.validation_status and rev.validation_status are defined as RAW.
When I run this update I get a message that says ORA-01407: cannot update ("MODN"."MN_SALE"."VALIDATION_STATUS") to NULL

But the column is defined as nullable no. What can this be?  If I select from the table with validation_status is null I get no rows back
so the table really doen't have nulls in that column.

update modn.mn_sale rev

   set (rev.INV_QTY , rev.validation_status)

• (select orig.inv_qty ,orig.validation_status from modn.mn_sale orig where orig.revERSAL_STATUS = 50 and rev.BACKWARD_REF_ID = orig.SALE_ID and ABS(rev.INV_QTY) <> ABS(orig.INV_QTY) ) where rev.revERSAL_STATUS = 30

Thanks Received on Wed Oct 18 2006 - 19:48:36 CDT