Whenever I log out or am timed out of the backend since I updated to 3.0.6 I am getting a blank page - no error reporting is happening from any of the flags I have tried in htaccess or configuration. What I have noticed is that a php file called touch.php is being created in root and administrator with no content. It took me a while to figure this out but if I delete the touch.php from both locations I am again able to login to the backend but it reappears each time I am logged out again.
Any ideas if this is something to do with the latest update as it wasn't happening before I updated but is doing now.
Found the cause. Enabling the pay with Amazon plugin causes the touch.php to appear - if this is disabled it seems to not be affected at all.
Please download the reupped zip file, the amazon plugin got truncated due the tars, see here http://issues.joomla.org/tracker/joomla-cms/6133