Trellis graphics and clipping

On 29-Jul-01 Ted Harding wrote:

Even when displayed in the R Graphics Window, there is
some clipping (the extreme top, bottom, left and right
edges are not there, so that labels, and parts of numerical
scale markers all round, have been clipped off).
[snip]
When I switch to the "postscript" device, with the comamnd
'postscript(filename,...)', the result is even more clipped,
[snip]
I've tried playing with all the obvious (to me) parameters
which I can find, but it has not effect on this.

Follow-up.

I've tried the following:

  hgm<-histogram( ~N | B , xlim=x(0,5), layout=c(5,5) , ... )

  print.trellis( hgm , position=c(0.075,0.075,0.925,0.925) )

so as to force down-scaling of the graphic, and now everything
is fully displayed in X11: top and bottom scale annotations,
bottom label and side label, and all the histograms. No clipping
whatever. No problems.

Except that there's an error message:

  Error in unset.gpar(vps[[1]]$gp) : trying to reset with 10

Next, I've done

  postscript(horizontal=FALSE,onefile=FALSE)

and again

  print.trellis( hgm , position=c(0.075,0.075,0.925,0.925) )

(getting the same error message)

and then looked at the resulting PS file. This is again slightly
clipped (on the left, as it happens, so that the left label lacks
the tops of its letters), but everything else is absolutely fine.
OK,

  print.trellis( hgm , position=c(0.1,0.1,0.925,0.925) )

(same error message).

Now, Lo and Behold, when I view the PS file there is no clipping
at all. Good!

So, apart from this error message (which must mean something, but
nevertheless goes with perfect output) all now seems fine.

But it still puzzles me that one has to grope for the correct
"position" parameter settings for each device.

Is there a way to pull all this together?