If for some reason you have an error when trying to execute an svn command (like status, info, update or another one) and the cleanup command does not resolve anything (like saying the same error ...).
You can fix the issue by removing the WORK_QUEUE in the sqlite database with this commands :
sqlite3 .svn/wc.db delete from WORK_QUEUE; .exit
This will open the sqlite database, and removing the data from the WORK_QUEUE tables, you can also check the list of file inside it by using this command :
select * from WORK_QUEUE;
For more information check this article from Changil Kim : http://changilkim.wordpress.com/2012/12/10/svn-cleanup-fails/