[R] apache and php running R

[Bill Szkotnicki]

Hi,
I am trying to run an R program ( linux ) from php to create a graph and 
other things for a webpage.
The R program is stored in /tmp and to create a graph I use the png function
i.e.
 png(filename = "/tmp/trialcsvt8wafB.png", width = 720, height = 480)
But when the userid apache ( which is what the httpd runs as ) runs this 
I get the following error
X connection to localhost:11.0 broken (explicit kill or server shutdown).
and yet when I run it as a normal userid it works fine.

Does anyone know how to fix this?

Thanks,
Bill