>The problem is that under some circumstances that a .NULL. appears for 1 field coming
>from table C (INV in this case) where there are values for all the other fields coming
>from table C.
Oh, you mean like you said in the very first line of your post? *chagrined look*
Can you repro the problem with a couple rows of data?
Is it always the same rows that have the fake NULLs?
Is it blank data that's becoming null, or non-empty values?