From: DeskNow Knowledge Base
http://www.desknow.com/kb/

The applet disconnects frequently - I have problems staying connected / sending messages to other users
http://www.desknow.com/kb/idx/8/059/article/

Try disabling the usage if NIO for higly-scalable communications: edit the file Messenger.cfg and set

PlainConnector.NIO FALSE

then restart DeskNow.

If this does not work, please enable the Java Console logging (see http://www.desknow.com/kb/idx/8/033/article/ ) and send this log to our support team.