I have an SVN repository (hosted on Dreamhost) with needs-lock set on binary files. It sometimes happen that, while committing files locked and modified by me, the commit fails
right click on the file you want to unlock, go to Subversion and click lock
then select checkbox steal existing lock and apply with OK
right click on that file again, go to Subversion and click unlock
lock the file with --force
svn lock --force path/to/file.ext
and unlock it again
svn unlock path/to/file.ext