After Ship Confirm the Tax_Category are removed from ILScreen in Partial Shipment

HI Gurus

We have recently updgraded from R12,0,06 to R12,2,5 it was noting After Ship Confirm the Tax_Category are removed from ILScreen when Line are back ordered

this issue we have faced in cases of partial Qty

Create a sales order for 10 qty, stock available of 6

- Apply tax category on the line in Local SO form

- Run pick release for the line

- Line status becomes Picked Partial, with 6 qty picked

- Ship confirm the line

- The tax category from the line created and closed for 6 qty is removed leading to non generation of excise invoice. The other line for 4 qty still has the tax category.