[R] png scaling problem

[Knut Krueger]

scaling<-4
xywidth<-480
resolution<-150
png(filename = "c:/r/anschluss/plots/4.png", width = xywidth*scaling, 
height = xywidth*scaling,pointsize = 12, bg = "white", res = 
resolution*scaling)
......

barplot(xrow,col = barcolors,cex.axis=scaling, ylab="mean time till attachment in sec",cex.lab=1.2*scaling) 

I tried to scale the barplot but there is one strange result:
scaling=1
http://biostatistic.de/temp/1.png    --- the ylab is ok

scaling=2
http://biostatistic.de/temp/2.png    --- the ylab is not ok

scaling=4
http://biostatistic.de/temp/4.png    --- the ylab is terrible

is there any better solution to scale the resolution and the width/height?


with regards
Knut