When I use wand of speed, instead of just working and my demigod continuing on his/her merry way to where I told it to go, the DG instead stops and acts as if it is idle (attacks whoever is near).
I would expect an item like wand of speed just gives a burst so if I told the DG to run, it will run and the speed will help (lets say I am chasing a DG to finish it off OR I am being chased, that critical half second could mean the difference between life and death).