*Every* segfault is a bug (at least as far as my experience and my imagination go). So, look in the bug tracker for amsn (amsn.sf.net -> dev -> bugs), see if any bugs sounds like what you're experiencing. If not, talk to the devs (try #amsn on freenode if you do IRC) about what information they need from you for a proper bug report.
If you are not allergic to compiling the code yourself, compile it with debugging symbols, set the core file max size to unlimited (help ulimit | less; ulimit -c unlimited). Reproduce the segfault, open up the core file in gdb and generate a backtrace. I'm sure the devs will happily help you with this.
Also, if you haven't already, read "How to ask questions the smart way" (
www.catb.org/~esr/faqs/smart-questions.html) and "How to report bugs effectively" (linked to in [HTAQTSW]), especially the latter.
Until it gets fixed, take advantage of the flexibility and redundancy offered, and use a different client. Just a thought.
hth --Jonas