If you are in the compose window and you want to pick an address from the
address book, you click on the address icon, it pops up the window with
your personal addresses, then you click on an address and it crashes.
I've tried on 2 installations of RH 6.2 (one is an upgrade from RH 5.2 and
the other is a brand new one).
I've also tried with the new version of netscape 4.74: same thing.
I've tried with new addresses (created right now) and with old addresses
from old 4.0x netscape.
I've tried with a brand new session of Netscape (removing .nescape dir
before to start netscape) and it crashed

My feeling is that it's a problem with XFree86...

Ciao
Daniele