I'm not sure how long you've been trying it with IMAP+, but I as well tried that a while ago thinking it solved it. But like my original description says this happens in sporadic time periods. After using it with IMAP+ for a little while the same behavior happened with the folders disappearing.
** Changed in: evolution (Ubuntu) Status: Triaged => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/673591 Title: All IMAP Folders keep disappearing, reappear after opening "Subscriptions" -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs