I used the upgrade-3.211.63-to-4.211.64-1.sh script to try to upgrade my system. I was at 3.211.63-10 and the script constantly told me that I could not upgrade because my version needed to be upgraded to at least 3.211.64-7 first. The version number threw me for a while thinking that there was a script to upgrade the 3 version to Centos 6.4 but then realized that it was probably just a typo in the script (it is). I then figured out that the > comparison was failing because it was considering 10 to be less than 7. I just removed the comparison from the script and the upgrade ran without a hitch.
(MODERATOR EDIT: THE SCRIPT HAS BEEN UPDATED NO NEED TO MAKE MANUAL CHANGES NOW)
I got around that by editing the /etc/schmooze/pbx-version file, and changing 3.211.63-10 to 3.211.63-9. I wouldn’t normally mess with system files, but in this case it seemed pretty harmless.