Bar chart: break long bars

Dear all,

I have a problem with my stacked bar charts. I have one very long bar, hence
I would like to break the x-axis at a certain point so that the shorter bars
can be seen better.

Here is a cooked up example:
library(lattice)
group<- rep(1:3,10)
x<- runif(30, 0, 100)
y<- runif(30, 0, 100)
x[5]<-500
z<- rep(seq(1:10),3)
z<- z[order(z)]
frame<- data.frame(group,x,y,z)
barchart(z ~ y +x | group, data=frame, stack=T,
          col=c("white","grey"),
          xlim=c(0,600))

If you run this code, there will be one very long bar in the chart on the
lower right-hand side. All other bars are by construction shorter than 200.
How could I now break the x-axis somewhere around 200 and then continue at,
say, 500? Sorry, I was just unable to figure that out myself.
And given that I'm already posting something, I have another little
question. How could I, in the same graph, turn off that little orange
indicator for the group appearing in the strip?