[R] Problem with clipping in Lattice, and closing a postscript device

[VU HA]

I would appreciate any answer to the following two problems I am having with 
the Lattice package.

First, in most instances of using Lattice, the produced graphs have some 
clipping, usually at the borders of the encompassing rectangles. An example 
of this is here: http://cs.uwm.edu/~vu/lattice.pdf where the clipping occurs 
in the first half of the X axis.

Second, when printing to a postscript file, for example, using the command

trellis.device(postscript, file = "test.ps", color = TRUE)

to initialize the output file and then the command

dotplot(y ~ x | z, ...)

to draw the graph, the postscript file test.ps still has zero size. If at 
this point I quit R, then test.ps will contain the output graphics. Is there 
a way to "flush" the trellis device without exiting R?

Thank you very much in advance.

Vu Ha, PhD.
Information and Decision Technology
Honeywell Aerospace
3660 Technology Dr.
Minneapolis, MN 55418
612-951-7114