Have you tried recently? libotr version 4.0 (released last year) added handling of this very issue. Both parties need to be running >=4.0, but it shouldn't break down horribly in this scenario.

I did indeed try with adium about a month ago. Don't know if adium hasn't updated libotr yet or if my buddy had an older client.

He ended up having to block me on AIM because my adium instance at home went into a resend-frenzy while I wasn't even at home...