I just had a battery problem and ended up with a corrupted log file (about 1k of trailing 0x00 bytes). The effect was that trying to open the chat corresponding to that log file caused mcabber to crash the terminal.
WORKAROUND: remove trailing 0x00 bytes in log file. I'm pretty happy with that.
I am reporting this anyway so affected people will know (or feel like writing a proper fix).
Thanks for mcabber, I really like it so far! :-)