I already mailed this to the list but got no response.
I first noticed this when freetype support was added to X
in rawhide. So I think it's freetype related. I run X
in 16bit 1024x768 but I think this is not relevant.

The bug:
-start netscape from an xterm
-click op the mail icon
-switch back to the first window
-stop loading whatevee it's loading there
-close the navigator window -> bus-error, takes mail window
 with it.

This also happens randomly when browsing and you close the
first window. It only happens when you close the first
browser window. The method above is pretty descent in
reproducing it. But doesn't reproduce it always.

I do use truetype fonts in netscape through xfstt, but did
that before with plain 5.2 too and that worked fine.

Also when i noticed this bug with rawhide I did a lott more
testing and disabling truetype support al together, and thus
not choosign truetype font's in netscape still triggered the
bug. I think this is really a netscape bug. But it's somehow
triggerdd by the freetype support so maybe thats doing
something wrong