Create drawing model - drawing model seed


When I create a drawing from placing a callout the dialog "create drawing" shows. I often want the new drawing in a separate new file. So I thick the box for Filename and click the create drawing:

As shown in the picture, the seed for the new file is set to designseed. Even though the configuration variable MS_DRAWINGMODELSEED is set to Drawingseed.dgn (which is the name of the drawingseed, and placed in the same folder as the designseed.dgn). 

(The same goes for sheets). 

Is this how it should work, or is there something wrong with my configuration?