Hi ,
I have been facing this issue with the Sharepoint 2010 Web Application , The Web application is Claims based and has a custom membership provider .
The issue that i am getting is that whenver i try to active some custom feature or even the publishing feature i am getting access denied .this is also the case when i try to create a site collection using a sharepoint timer service or using a standalone application .THe account that i am using is the farm administrator account .
The strange part is the features do get activated using powershell or Stsadm
i have tried quite a few things including configuring the "Superportaladmin" and "supereader" ,Still no luck
Any Help is much appreciated .