plot order in spplot with sp.layout

Dear list,

when doing the following, the grid is plotted on top of the sp.layout-item:

data(meuse.grid)
coordinates(meuse.grid) <- ~x+y
gridded(meuse.grid) <- TRUE
data(meuse.riv)
meuse.riv <- SpatialPolygons(list(Polygons(list(Polygon(meuse.riv)), 1)))
spplot(meuse.grid, sp.layout=list("sp.polygons", meuse.riv))

?spplot says:
"for grids and polygons sp.layout is drawn afterwards (so the item will not be overdrawn by the grid 
and/or polygon)."

Do I misunderstand the documentation or is this a bug?

Thanks!
Tom

Technische Universit?t M?nchen
Department f?r Pflanzenwissenschaften
Lehrstuhl f?r Gr?nlandlehre
Alte Akademie 12
85350 Freising / Germany
Phone: ++49 (0)8161 715324
Fax:   ++49 (0)8161 713243
email: tom.gottfried at wzw.tum.de
http://www.wzw.tum.de/gruenland