Some time ago, we noted that Spark seems to have problems with certain passwords:
Users at our site are still experiencing this issue with Spark 1.1.0. They are able to log in using other XMPP clients, but not with Spark. I would send a protocol trace, but I’‘m not sure how I can either open the client’'s XML debug console before login or configure Spark to communicate plain-text to allow traffic capture prior to SSL tunnelling to the server.
We will soon upgrade our server software, but at the moment it’'s still running Jive Messenger 2.3.0. Our server is configured to authenticate clients to an external LDAP server. Our LDAP logs indicate that the server is not sending a bind operation for the failed logins, so this may be an interaction on the server end; however, other clients are able to authenticate using these credentials, so if there is something on the server side, it may be triggered by some interaction with the Spark client.