[R] simple postscript question

[Troels Ring]

Dear friends - following instructions via google I managed to have the 
following eps accepted well in words - but I cannot get a decent 
postscript print from Gswiew, latest edition. The ylab is printed only 
in half, the par(mar seems inconsequential. I hope you will forgive this 
simple question.
Best wishes
Troels Ring
Aalborg, Denmark
Windows 7, R 3.0.1

postscript(file="fig1.eps", horizontal = FALSE, onefile = FALSE,
pagecentre=TRUE,paper = "special",colormodel = "rgb",width=8,height=8)
par(cex=1.25,cex.lab=1.25,cex.axis=1.5,mar=c(5.1,5,4,2))
xyplot(Ammonium+SID~time|GRP,comb1,type=c("p","smooth"),
ylab="Ammonium excretion (line) and SID excretion (stippled), mmol/day")
dev.off()

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