Like virtually all of the Alice objects, the shapes seem to have been designed by different people and without a generally agreed on standard for texture (UV) mapping. Good for variety and evaluating different approachs - but a problem with simple things like this.
While the shapes in general map at
about 512 pixels per meter, there are many exceptions, including the cube. For that particular shape, I recommend just using the box, which does map OK.
If you are going to do a lot of this, I recommend making a set of your own shapes with the texture mappings you want and importing them into Alice. There are instructions elsewhere in the forum and some simple shapes for import at
http://www.alice.org/community/showt...ighlight=shape .