Oh, this was my first guess, but mentioning of Save password box drove me away. This is called SSO (Single Sign On) i believe. I dont use this and havent ever tried to setup, but i’ve heard this can be very cumbersome. I think you will have to use at least 2.6.0 Beta 2 or maybe even newest SVN versions to get working SSO support in Spark (SVN versions: http://www.igniterealtime.org/community/docs/DOC-1822)
Try searching forums for SSO, Single sign on and slushpupie posts. I have found this one http://www.igniterealtime.org/community/docs/DOC-1362
And it says you can use 2.5.8 version, so maybe newest version is not required after all.