After upgrading to wp 3.1.3 and having wp-cleanfix on the last version 1.7.6 the following happened:
I could not access the network admin pages and the admin pages of the main blog of a multisite network anymore.
All normal blog admin pages worked and even the wp-cleanfix worked on those, but access to the admin sites of the network and the main blog were restricted (white screen).
After moving the plugin in a different folder it worked again.
Any idea why this happens and if there is a chance to fix it? Liked the plugin and would of course want to use it again.