Yea if your going to roll back I would recommended doing server and client side at the same time.That's actually what I did as well on our pack's server. However, there seems to be a weird thing happening when clients using the latest version run opis while on a server with the previous version. It only affects the client after they run /opis - the get a fatal error and kicked from the server, and can't reconnect until they restart the client.
Not that big of a deal, considering only server admins run opis anyway, but I figured I'd give the heads up. It's better than having no opis at all and running into other lag issues, not being able to find out what they are. (Glares at Draconic chests.)
Anywho, ProfMobius has some quality mods, so I'm sure we will see a fix soon.