Items invisible

Hi all, ive got the following problem with my RTSStarterkit:

im trying to get some items in my world using ItemData datablocks like this:

datablock ItemData(Potion1)
{
// Mission editor category, this datablock will show up in the
// specified category under the "shapes" root category.
category = "Health";

// Basic Item properties
shapeFile = "~/data/shapes/items/potion/potion.dts";
mass = 1;
friction = 1;
elasticity = 0.3;

// Dynamic properties defined by the scripts
pickUpName = "a health potion";
repairAmount = 50;
};

and this:

function ItemData::create(%data)
{
// The mission editor invokes this method when it wants to create
// an object of the given datablock type. For the mission editor
// we always create "static" re-spawnable rotating objects.
%obj = new Item() {
dataBlock = %data;
static = true;
rotate = true;
};
return %obj;
}

both were kind of copied from garagegames (sorry about that) so they should be working, at least thats what I thought. The file with the datablock in it is executed from game.cs where the other datablocks are loaded too.
Everything looks fine so far, right? Well, when I fire up my game and I spawn this test object (either through the mission editor or through a test-function) it does not show. When I go to the mission editor inspector function, I can find my object, and it indeed does have the right datablock, rotation, position and all the things you'd expect, and when I have an echo through the console like this: echo(%obj.getDatablock().shapeFile); it does return the right value however I cannot see it, and I also don't see why not.

Thanks for reading (and maybe some help)

P.S. The file DOES exist and when I try the same with the standard crossbow or crossbowammo they have the same problem.