We at times need to add an attribute to a posted invoice.  We go to Invoice Adjustment, but if all we do is add the attribute to an existing row without changing the GL distribution in any way, FE does not recognize the addition of an attribute as a change to the invoice.  Thus, it will not post the adjustment.  What we have to do is zero out the existing line and create a brand new line with the exact same info, and adding the attribute.  It works, but it makes a mess of the GL due to all the reversals and adjustments.