Here goes!  We had a user enter the part number as the issue quantity, normally no problem, just reverse the issue.  Well, the part number was 9 digits long (5,555,555 million) so the issue worked.  However, I found that when I tried to reverse the issue I got a INVTXN with zero quantity.  The problem appears to be that the field size is 13.4 which works for a positive number, but a negative number needs the "-" sign, and does not work.  The work around is to split the 5,555,555 into multiple transactions not to exceed 999,999 when doing a credit!  By the way, it also messed up the quantity in WIP and AVGC on the item because these are being dynamically incremented.

You can also fix the average cost through IN-K even if there is no quantity.