> typeinfo for QDomNodereferenced from libsmokeqt expected to be defined in libqt.3.dylib

Hmm, not sure. I didn't get these errors. You are following the
instructions in the INSTALL very carefully, right?

Let's work through this.

If you want to, (and it might be a good idea), you should be able to
rebuild qt without any ill effects. If you followed the directions in
the qt INSTALL file, you should just be able to go to /Developer/Qt and
follow the INSTALL instructions again. You're gonna want -thread, but I
don't think anything else should matter much. I used these flags,
mostly because that's (almost?) exactly what the qtruby INSTALL file
said to do and by now I was paranoid about things like configure flags,
but I think it should work just just about any reasonable flags. (oh
and btw I used qt-mac-free-3.3.5 as well)

-system-zlib -qt-gif -plugin -imgfmt-mng -thread -no-stl -no-exceptions
-fast

If I were you I'd delete your qtruby tree and unpack it fresh, then
read and run this script:  http://hans.fugal.net/src/qtruby-tiger.sh