How to get an inventory reservation to decrease?

Hi, 

I am creating a reservation, and I want it to decrease when I consume the material (using the Miscellaneous Transaction screen).  However, even after I use part of the reservation, the quantity in reservation still remains the same.

I can see this in the report "Item reservations report".  The column "Reserved Quantity" shows the correct quantity I first reserved but I would have thought that the column "Remaining Quantity" would be decreased by the quantity issued.

I searched in the report what was shown in the column "Remaining Quantity" and I found out that this was the "Reserved Quantity" - "Completed Quantity".