A follow-up, for what it may be worth... Typically, when gajim starts up for me, it automatically joins a groupchat after entering my account password, and the exceptions being thrown appear to relate to that.
I have gone back to 1.0.3-1 (compiled from source) so that I have a working gajim and can continue with life, but if anyone wants me to try out anything with the 1.1.0+ source to reproduce/diagnose this, I'd be happy to give it a shot. -m