Some changes to quartz()

Thanks to Prof Brian Ripley.

In answer to the message "gray grid on quartz()", he wrote

Now, considering the use of image() on quartz() in R 2.7.0, there  

is a (equally vague) bug report and thread at

https://stat.ethz.ch/pipermail/r-devel/2008-May/049650.html

that seems similar to your comments.  Simon Urbanek has made some  

changes to quartz() to alleviate this, so please

try a current R-patched  build.

I am working with

platform       powerpc-apple-darwin8.10.1
arch           powerpc
os             darwin8.10.1
system         powerpc, darwin8.10.1
status         Patched
major          2
minor          7.0
year           2008
month          05
day            15
svn rev        45703
language       R
version.string R version 2.7.0 Patched (2008-05-15 r45703)

but the ugly grid still appear when I use image() function.

What's wrong?