Force purge in designer

 Dear All,

I am trying to delete an application from the repository which is double while importing. Now i want to get rid of the extra appication by force delete, force porge but nothing is working. I am sure i did all the list checkout and see any of the modules/ plsql objects are checkedout. I couldnt get any name in the list.

I am using  version-10.1.2.0.2
configuration-4.0.12.97.6
build-10.1.2.6.18
and operating system is win 2003 sp 2

I get the following error:

CDR-02000- cannot delete application system
cause- an error prevented the deletion of this element.
action- see other errors in the stack to determine the cause.