[R] lattice-dotplot: resize axis

[René Mayer]

dear all,

I want to make a dotplot with ratings from Items in 6 ItemsGroups.
I reordered the items by rating within each group.
I plotted the items by rating conditional on ItemGroup.
The ordering works as I wanted but my y-aches labels (items) within  
each ItemGroup are now unequally spaced, e.g., in some panels there is a
gap between one lower rated item and the next higher, to give a picture

items=a,e,f,g

ItemGroup=n
-----------------
g|      .
f|   .
e|  .
  |
  |
  |
a| .
-----------------


How can I correct this? What have I overlooked?

# code i've used (from latticeExtra/utilities/resize panels)
library(latticeExtra)


mean.ratings$item.name <-
     with(mean.ratings, reorder(reorder(item, rating),
                         as.numeric(ItemGroup)))
dpratings <-
     dotplot(item.name ~ rating | reorder(ItemGroup, rating),
             data = mean.ratings, layout = c(1, 6), xlim=c(1,6),
	    aspect = .1,
             scales = list(y = list(relation = "free", cex=.5)))

## approximate
resizePanels(dpratings,
              h = with(mean.ratings, table(reorder(ItemGroup, rating))))

thanks,
René