Elastix Upgrade Nightmare

I thought it would be relatively trivial to do an upgrade from Elastix 1.5.2-2 to 1.6.2-27. Initially it seemed this way. I ran:

# yum update yum
# yum update

When this completed, I logged back in to the system and saw that it was up to 1.6.2-27. What I didn't notice at the time is that I could no longer access the PBX tab in the web admin panel and that the system wasn't interfacing with my lines or extensions anymore. Once I discovered that this was the case I immediately went to search the Elastix forums (and the web at large) for answers. I largely came up empty handed. The few threads that I did find didn't fully match my situation:

• Can't enter to PBX menu - in this thread, the premise is the same. An update from 'yum update' and the PBX menu goes blank.
• PBX menu does not work with new install - different premise and version but the same problem.
• ?menu=pbxconfig en blanco - I had this tab open but I don't think I read it. It has the solution but in passing. It also has the fix for some others' problems with DB connect.

Ultimately I was able to draw the conclusion that there is a tie-in between FreePBX and Elastix's PBX menu. I accessed FreePBX and noticed that nearly all of the modules were disabled because they were outdated. I updated them and the PBX menu problem went away. Somewhere I have a copy (probably outdated) of Elastix without Tears that probably tells me this as well. Nonetheless I hope that this helps save someone else's time finding and fixing this issue.

Update: A boot option change (the default kernel to boot) was changed in my troubleshooting of the PBX menu thingy and when this was reverted the line card came back online. The reason for this is because the DAHDI kernel driver is only installed for a particular kernel. I apparently have a second pair of kernels. Not sure where they came from though.