im not sure but dont your entitybox coords have to start from the corner? it seems by specifiing 0,0,depth you are starting from the center of the mesh??
shouldnt it be:
when you create the mesh at 0,0,0
entitybox entity,-width/2,-height/2,-depth/2,width,height,depth
shouldnt it be:
when you create the mesh at 0,0,0
entitybox entity,-width/2,-height/2,-depth/2,width,height,depth