I am using this link http://msdn.microsoft.com/en-us/library/bb861909.aspx
The adding a SafeControl to the web.config works good. But the removing does not work! What is wrong?
Here in comments you can see the same problem http://blog.thekid.me.uk/archive/2007/03/20/removing-web-config-entries-from-sharepoint-using-spwebconfigmodification.aspx