Created attachment 14715 [details]
Testcase, C++ sourcecode

Use this together with a Makefile that looks something like this:
INCLUDE := -I/usr/qt/3/include -I/usr/kde/3.4/include
LIB := -L/usr/qt/3/lib -lqt-mt -L/usr/kde/3.4/lib -lkdeui -lkdecore

main: Makefile main.cc moc.cc
	g++ -Wall $(INCLUDE) $(LIB) main.cc -o main

moc.cc: Makefile main.cc
	moc main.cc > moc.cc

I finally figured out something that is almost a workaround: I draw the top-left and bottom-right pixels in another colour:
		painter.setPen(Qt::NoPen);
		painter.setBrush(QBrush(QColor(0, 0, 0), Qt::SolidPattern));
		painter.drawRect (0,  0,  1,  1);
		painter.drawRect(15, 15,  1,  1);
 Then everything except those 2 pixels are drawn correctly. Something really "funny" is going on somewhere.

Still relevant to recent KDE version?
If not please close the bug.

Thanks,

Lex.

Please port the application to QDockWidget, because KDockWidget is no longer maintained.