The bug still occurs with Emacs 22.3.1. The attachment kdump-mp6495.tar.lzma contains the dump files obtained with
ktrace /Applications/MacPorts/Emacs.app/Contents/MacOS/Emacs \
-q -no-site-file -eval '(setq inhibit-splash-screen t)'
and kdump, and the corresponding environments. In the Emacs window, I typed "asd" and selected it with a double-click. Then I quit Emacs with C-x C-c.
*-fail when Emacs has been started from screen (see above).
*-ok when Emacs has been started from a normal iTerm tab.
In kdump-ok, the PID has been changed to the PID from kdump-fail in order to be able to do a "diff".
It seems that the main differences in the kdump files are the failures of shm_open in kdump-fail: "shm_open -1 errno 2 No such file or directory".