Beat, this is very cool. I have been struggling with this issue for what seems like weeks, and am glad to have this fix. I am on:
CB 1.3.1
CB Subs 1.1.2
MyCommunity template
Like clockwork, at 6 p.m. each day (Eastern US time, so GMT-5) and until midnight here, the system would not allow logins, with the "Session expired or cookies disabled" message.
This change seems to have fixed it.
I really love CB and CB Subs, and am looking forward to be able to go into production with it with some confidence that people will be able to log in.
-- Jordan