VAT and shipping fee are applied several times after order update

[biletnikov]

Hello all,
we faced a strange problem which appears for any order with more than 1 drop shipment items.

Example, we created an order with 2 drop shipments items for each item we have the shipping group.
This order:

Product 1           €192.77
Adjustment Sales Tax Jurisdiction Germany [DEU] Rate 19%   =  €36.626  


Product 2           €63.74
Adjustment Sales Tax Jurisdiction Germany [DEU] Rate 19%  = €12.111


Shipping and Handling  :€5.00
 
Shipping and Handling  :€9.00


Items SubTotal €256.51
Total Other Order Adjustments €0.00
Total Shipping and Handling €14.00
Total Sales Tax €48.74
Total Due €319.247
 
After that, we tried to update the order, clicking the action button "Edit Items" and we change NOTHING and press "Update items" ! As we understand, nothing must be changed, but the order is changed:

Product 1           €192.77
Adjustment Sales Tax Jurisdiction Germany [DEU] Rate 19%   =  €36.626  


Product 2           €63.74
Adjustment Sales Tax Jurisdiction Germany [DEU] Rate 19%  = €12.111
Adjustment Sales Tax Jurisdiction Germany [DEU] Rate 19%  = €12.111


Shipping and Handling  :€5.00
 
Shipping and Handling  :€9.00

Shipping and Handling  :€5.00

Items SubTotal €256.51
Total Other Order Adjustments €0.00
Total Shipping and Handling €19.00
Total Sales Tax €60.85
Total Due €336.36

as the result of our update we have additional Sales Tax for the Product 2 and additional Shipping and Handling fee: 5 EUR

Why it is so??

Is it a bug?

For one drop shipment item all is ok, for 3 and more items adjustments are added to the last item in the list.

Thank you.