Unable to enter world with 3.3.1

[Drawde]

After downloading the new minilogin, and adding the eqmessages table
as someone else suggested, I can now log in and create a character. However
when trying to enter the world, I am booted back to the server selection
screen (directly, without getting a "disconnected from server" message).
This is on a local server. The info in the server windows before starting up
EQ indicates that they're all connected to each other properly. However, on
exiting, the zoneserver windows show errors related to "unexpected packet" (though
I've seen this error with earlier EQEmu versions, with no apparent effects) and "error
adding lootdrop to NPC" errors (though the loot tables haven't changed since 3.3.1, and
the loot DB addons sourced in without any errors; again, this error has appeared in the past
without any apparent effect).
This error seems to happen whatever race and class combination I choose. It's very similar
to the zoning bug in 3.3.1 (where you'd sometimes get kicked back to server select when using
#zone, and the same thing would happen when you tried to re-login as that character; you had to
use EQEmuAdmin or #movechar to get them out of the zone). As far as I can see the error is not
related to IPs or .ini files being set up incorrectly, or DB errors.
I'm using the latest version of my DB addon, with quite a lot added to it since the last released
version, but all of it seems to be 3.4-compatible and sourced in without giving errors.