[support] Very disappointed, frustrated and concerned Drupal 7 problem

[Roger]

<snip>Check your PHP error logs. Almost sounds like PHP is running out 
of memory. Jamie Holly http://www.intoxination.net 
http://www.hollyit.net </snip>

thanks I thought so too.
I'm running fully updated Fedora 18 with latest php, mysql, httpd, etc
I tried setting memory_limit to 128M then 256M then 512M all have no 
effect on the problem.
I'm beginning to wonder if it's something in the changes to httpd.conf 
but have checked that against advice on google and it seems ok.
The WSOD only affects certain functions and not others.
I would have thought that Views and Permissions required more memory 
than pretty much anything else but they're unaffected.