image() to Rplot.pdf

Hello all members!

I work with version 2.7.1 RC (2008-06-15 r45927). When I save as  
Rplot.pdf a quartz() device generated with image() function, still  
appears gray rectangles over the image ( the image in the quartz()  
device is all right! )

That is a rendering issue in Preview (zoom in and you'll see that  
there are no lines), it is unrelated to the Quartz device. The PDF  
itself is fine, but Preview doesn't correct for anti-aliasing effects.  
I think using Acrobat may work (I don't want to install it since it  
messes up the system so I cannot check).

Cheers,
Simon