My group encountered the same problem with connecting to .42 and decided to roll back to .38 and stay there.the new update, .42 fixes this issue, if you are still on .41 then yes, you will have to disable Wawla.
EDIT: would just like to say that also .42 has some server-related issues with connecting btw, i know this is an unstable pack and shouldn't really be meant for servers yet but i thought i'd throw one up xD im not entirely sure what's causing the issues however but you get a connection closed error when connecting, seems that either the server or client isn't able to send/receive something fast enough
I doubt we'll see any more 1.8 updates for this pack though, with 1.9 ramping up quickly.