g_utf8_validate failed

[Peter Bloomfield <PeterBloomfield MindSpring com>]

With Balsa-2, I've found that certain messages give a deluge of 
messages like:

(balsa:29507): Gtk-CRITICAL **: file gtktextbuffer.c: line 476 
(gtk_text_buffer_emit_insert): assertion `g_utf8_validate (text, len, 
NULL)' failed

Said messages contain characters 0x93 and 0x94, and presumably these 
are the problem. I believe it's cr*p from M$ apps--what can we do about 
it?