The little differences are rather usual, unfortunately.
Not every minor version has a binary update, most only add new art or update configurations. The client reports its binary version, but the launcher reports the data version, which may be a little more recent.
The client (psclient.exe) has version 0.5.9.10; the installer of version 0.5.9.11 updated a configuration file to the new game server address, and version 0.5.9.12 also included some new art files. Your installation is up-to-date.