My first guess would be that you are using a bad link to get to fullpage chat. A link like <a href="http://perlmonks.com/?node_id=3184&displaytype=raw">chat</a> will log you out unless you logged in via perlmonks.com [ as opposed to www.perlmonks.com or any of the other 4 host names matching /^(www\.)?perlmonks\.(org|com|net)$/ ].

A valid link would be like <a href="/?node_id=3184&displaytype=raw">chat</a> or fullpage chat. Try that one.

                - tye