Odd behaviour after recent upgrade 5.0.5 -> 5.0.23

[Cyberian]

Hi,

As the title states I experienced a number of problems after a recent upgrade - The upgrade completed with no warnings or errors and I went ahead with a backup which completed fine as well. Then found that I couldn't access the administration panel a half hour later, it just would not appear. Logging into the shell and issuing a "zmcontrol status" gave me the error of

"Unable to determine enabled services from ldap.
Enabled services read from cache. Service list may be inaccurate."

which I tried to work through using the forums, but my host file seemed fine, my MX records were in order and nothing else seemed amiss - so I kept wandering through the forums looking for other options. Then I came here too ask for advice on where to go next since I couldn't find any more information that seemed relevant and when I went too get a copy of the error message I find that everything is working fine - mail is flowing in both directions, zmcontrol is saying that everything is working and the admin web interface is showing up. This worries me since I did no changes at all and have no idea what went wrong - is there a guide anywhere for things I could look at to try and determine if I have a deeper problem anywhere?

The current plan is too upgrade again to 6.X soon (within a few weeks once the workload lightens up, the upgrade to 5.0.23 was only because clam reached EOL and I read while error hunting that v5 reaches EOL once 7 hits?) - but if there is a problem I'd rather shoot it now than have it eat me during another upgrade.

Thanks for wading through this wall of text and any pointers would be appreciated.