We're switching to a new (pro) naming convention for Sanctuary renders.
It's a little more complicated but a tool to make this transparent is under development.
NOTE - the render monitor still understands the older (simpler) naming convention but VFX artists should use the new one to avoid clashes.
The inclusion of a version number in filenames means that the ability to update a shot via FTP is going to vanish any day now!
http://trac.modfilms.com:7861/trac/sanctuary/wiki/NamingConventions