Stock transfer order

Hi,

we have an issue in allocating inventory to Stock transport orders.

We are trying to manually allocate a specific amount of inventory to each of 4 STO’s. The problem is that we did the manual allocate and committed 20 case to each of the STO’s, but when we created the deliveries they created 20 on the 1^st STO, 22.13 on 2nd and 3rd STOs. 2nd and 3rd STOs have the quantity of 30 and 23.  Shouldn’t we be able to allocate what we want for a STO?

Please help.

Thanks in Advance.