Sidebar not appearing in manager. Any idea how to fix?

Hi,

I am not sure if this is directly the same issue, but i just experienced the sidebar vanishing from the manager and every other function stopped. Looking in firebug i found it failed to find /connectors/modx.config.js.php and /connectors/langs.js.php which it was because for some unknown reason all the files except config.core.php had vanished. I replaced them from the downloaded zip and da da daaaa the manager is back, i am still testing to see if this might have resulted in other errors. If anyone wiser than I can tell me if this fix is ok and why this might have happened that would be great.
Cheers
Karlos