[horde] Issues with getting webmail working

[Robert Smith]

Hello,

I'm putting together a horde webmail edition setup using the following:
centos 6.5
php-fpm 5.3.3
mysql 5.1.73
nginx 1.6.0
dovecot 2.0.9
horde/webmail 5.1.4

Using the PEAR installer, the webmail for workgroups install went quite
smooth.  Then came the cryptic "Error when communicating with the server."
message.

Initially, the message was due to requests like this being pushed through:

POST /services/ajax.php/horde/topbarUpdate

This was due to the incorrect configuration of the fastcgi in nginx.  Got
that worked out.

Now my error logs have gone silent, and the error message still persists.

My error logs:
/var/log/nginx/error.log - debug level
/var/log/messages - eh, no level
/var/log/php-fpm/error.log - default level
/var/log/horde - debug level
/var/log/maillog - default level?

Upon logging in to Horde Groupware Webmail edition, everything functions,
save for the mail.  Horde even tells me I have 1 unread message and 5 read
messages which is accurate with what's in the inbox.  I've been using
Thunderbird with dovecot for a bit, but want to get a nice webmail setup
working.  Not really sure where to go from here.  Is there a log I might be
missing?

I hope that I've covered all the bases for the needed information.  Yes,
I've searched around the list, the error seems common enough.

Does this have anything to do with my horde_core version being sub-2.12.0
and  horde version being sub-5.2 which is not yet released?  If so, if
there's a patch, I'm not afraid to go change the code, it's already not
working for my setup, so the worst that will happen is I trash it, and have
to re-install.

Thanks,
Bob