Segmentation faults with Mozilla 1.7.3 on Solaris 9

I am getting frequent segmentation faults running 1.7.3 on Solaris 9.
This is using the Gtk library mentioned in the release notes, and there
are no complaints about missing patches when the program starts. The
fault never seems to appear on startup, but only after some minutes or
some hours of usage. The faults are not tied to any particular user
action that I have been able to identify, and often seem to appear
spontaneously when the program is otherwise apparently idle. (I
typically have both the browser and the mail tool active, and so of
course they both can be triggering actions on their own such as checking
for new mail.) I have no problems of this sort when running Mozilla 1.6

If anyone has any suggestions as to how to deal with this or investigate
further I'll appreciate hearing them.

Thanks....