By default, Agent SVN will apply a lock to the file whenever the file is checked out and release the lock whenever the file is checked in.
This also means that if the file is already locked by another user then the check out will fail with a file locking error message.
This feature provides a way to serialise the access to the file and is designed to emulate the file locking behaviour of other source control system, for example Visual Source Safe.
This feature can be disabled by unselecting the file locking option found in the Agent SVN configuration dialog.