messaging system fails for some reason

[splitbrain]

I tried to send a message to a user here: http://irc.dokuwiki.org/index.php?d=2014-01-09#msg493758

dokuwiki reported back he doesn't know that user, even though he was seen just the day before: http://irc.dokuwiki.org/index.php?d=2014-01-08#msg493568

Maybe it's the underscore in the name?

[Klap-in]

Using @username: instead @username has same issue:

The next talk in the channel: 02:16 < Klap-innnn> @Klap-in: test 02:16 < Klap-innnn> @Klap-in test

results in respectively: 02:16 Couldn't store your message because there were 0 nicks known by database. 02:16 Stored your message for Klap-in.

http://irc.dokuwiki.org/index.php?d=2014-02-16#msg499399