Curious problem with #newweapon

[Panpiper]

I need to create a magic spear that is one handed. This should not be a problem, or so I would have thought.

I have a commander that was carrying an enchanted spear and shield, this being thematic for the commander. However if a player were to give the commander say, a magic shield, the spear would disappear. This because the spear is defined in game as a two handed weapon. So I need to define a new weapon that is 'called' a spear, that is actually a single hand weapon, and to equip the commander with that new weapon. So I created:

#newweapon 733
#name "Spear of Slaanesh"
#dmg 6
#att 1
#def 1
#len 4
#magic
#rcost 0
#end

Now in game when playing, the commander is in fact carrying a weapon called in game; "Spear of Slaanesh" with the listed stats. However, if I give that commander a magic shield, just like before, the spear is no longer equipped. !!!

The above described weapon does not 'copystats' from a spear, it is ostensibly as far as I know a completely unique new weapon. Why on earth is the game treating it still as a two handed weapon? Does the length of it default to a two handed weapon? Is there a command I can use to force it into a one handed weapon?