I finally was able to emerge -NuDav world, and revdep-rebuild passed the
system as clean.  However, when I try emerge -uDav world again, that same
message, or some permutation of it, is presented.

I have set the flags "dbus qt3support qt3 qt4" and so on.  So that's not
it.

I unmerged a number of the involved packages, that looked something like
"qt-*".  I did this just before running the more or less successful "emerge
-NuDav world".  A week ago, I ran "emerge -e world".  Perhaps I need to do
this again.

I've read a plethora of postings, such as a sticky post on the Gentoo
Forums, and some of these emails, as well as googling, and tried several
things.

When this all began, about three weeks ago, or longer, I noticed problems
with

   hplip
   python

I have python 3.1 and python 2.6 installed,  Some advice was seen to make
sure eselect is pointing to 2.6.  I also ran python-updater.

A new work week is starting, my system is responding normally, I will avoid
KDE4, and type this all shakes itself out, over the next week or so.

Thank you to those who have helped.  Good luck to others.

Alan