When attempting to save data into the postgres backend with gnucash, it's segfaulting on me pretty regularly in /usr/bin/guile. For example, once all I did was created a new file with "Common Accounts" and then save it as postgres://localhost/accounts and I got a segfault. Unfortunately it doesn't seem to be leaving a coredump anywhere. I've got guile-1.6.4-6.2, gnucash-1.8.4-1, and postgresql-7.3.3-3.
ulimit -c unlimited may help with core dumps. If you install the gnucash-debuginfo at http://people.redhat.com/notting/gnucash/, do you get a useful backtrace?
Hmm. I had ulimit -c unlimited in my dotfiles, but it was overridden in the window that I start with "xterm -ls" because of a competing line in /etc/profile. I've fixed that, so I'll get coredumps in that window from now on. As for the other stuff, I'm afraid I must plead "no time to debug." I already spent one all-nighter converting from cbb to GnuCash; I can't afford another one for a while :-).
Closing bugs from older, end-of-life releases. Apologies for any lack of response. Please attempt to reproduce problems on a current distro, such as Fedora Core 3.