Thank you. I will recompile Qt-4.8.0 with the "correct compiler". This is the first time, I've encountered that I needed to recompile Qt library on MinGW. I've been creating network applications, threading and so on. It went good as long as I didn't use an older compiler than Qt was build with.
Could my 64 bit Win 7 be the cause?
Is it possible to send the octave-gui application as zipped file to me, with your Qt-libraries: QNetwork, QCore, QtGui and QtOpenGL? That would be the only thing you need....