Welcome to LQ.
The Ubuntu 11.04 package 'qtstalker' is OK, and there are no updates
for the dependency libqt3-mt etc.
http://packages.ubuntu.com/natty/qtstalker
As "" nodes" in /usr/bin/include/qt3/qvaluelist.h "" looks like rubbish,
the only thing left to suggest, is to delete these files :
~/.qt/.qtstalkerrc.lock , ~/.qt/qtstalkerrc , ~/.qtstalker/*
( ~/.qtstalker/<folders> may contain files, you want to save.)
..