Several issues found after upgrade various version of Ubuntu to latest 14.04 LTS, luckily things are not that hard to fix.
ejabberd does not work, turned to be ejabberd was trying to get rid of asn1, and there were some problem caused by that. Though ejabberd fixed the problem right away, it seems Ubuntu took the wrong version. What you should do is upgrade ejabberd from 2.1.11 to 2.1.12 (later version may work as well, but I didn’t try),
and if you don’t know how to play with erl => beam compilation like me, you can just setup a Fedora VM and install ejabberd over there and copy eldap.beam from ejabberd package (NOTE: not the eldap.beam from ejabberd-eldap package) to the Ubuntu box.
RoundCube web mail does not work, it was cause by several issues. First, apach2 now only takes *.conf from site-enabled/ directory instead of former configuration of taking anything (I could have wrong impression on old release, but this is the cause). Second, dovecot’s configuration needs some tweak – you just need add a new section to 10-mail.conf with namespace inbox defined, which has inbox = yes inside. The last thing is, you need to enable mcrypt.ini in PHP’s apache configuration, you can do whatever you want, I just symlink mcrypy.ini from mods-available/ to apache/ and that’s it.
The new RoundCube interface looks good, I’m going to dig around to see if there is any other theme with different color, I always prefer light-blue/light-gray style.