[Evolution] Solution: Error loading address book

[Andrew Montalenti <ajm pixelmonkey org>]

I've been wrestling with this problem that has a lot of reports online
related to the mysterious message, "Error loading address book" followed
by:

We were unable to open this address book.

Please check that the path /home/foo/.evolution/addressbook/local/system
exists and that you have permission to access it.

Detailed error: Other error.

Someone once identified that this error happened on everyone's machine
who had built a custom version of evolution alongside their "production"
version.  Indeed, this was the case for me; I built Evo 2.26 via
jhbuild, but was only running it on a separate user account.  On my main
user account, I was using Evo 2.24.

The issue is the /etc/bonobo-activation/bonobo-activation-config.xml
file.  The developer docs recommend you add your local evo install to
this search path.  However, doing that on my machine causes the e-d-s
2.26 to run even with my 2.24 client.  Once I removed this path from the
config file, I could:

killall bonobo-activation-server
evolution --force-shutdown
evolution

and all was well again, my contacts opened.

Anyone know what the *truly* right way is to run two copies of e-d-s (at
different versions) on the same machine? 

Andrew