I had this problem too, when I tried changing a hostage model in CS.
I fixed it by calling DispatchSpawn(id).
Code:
public cmdArmory(id) {
new ent
ent = create_entity("team_armory")
new Float:origin[3]
entity_set_model(ent,"models/b_armory.mdl")
entity_set_int(ent, EV_INT_movetype, 6)
entity_get_vector(id,EV_VEC_origin,origin);
entity_set_origin ( ent, origin )
origin[2] += 100.0 //moves player out of the way 2 is up
entity_set_origin(id,origin)
entity_set_int(ent, EV_INT_solid, 1)
//entity_set_float(ent,EV_FL_animtime,2.0)
//entity_set_float(ent,EV_FL_framerate,1.0)
//entity_set_int(ent,EV_INT_sequence,0);
DispatchSpawn(ent);
return PLUGIN_HANDLED;
}