Return sale with discount error

[mmbwouters]

Hi,

I am using version 7.1h and I have discovered a problem when I ring a return sale with discount. For axample:
Artice 1 - 125.00
article discount 25% 31.25
Article 2 -100.00
article discount 25% 25.00
subtotal -168.75

So far so good, but when I press "reduce all items by percentage" for example 10% the register calculates 7.50 instead of 16.88. So the total of the return sale is now -161.25 and it should be -151.87.

When I ring up the same sale in the purchase mode it works just fine and the total is 151.87.

Michael