[PyQt] Ctrl+Y on document editor application

[Filip Gruszczyński]

I go to the /usr/share/doc/PyQt4-4.4.4-r1/examples/mainwindows/application

I run python application.py, a window is shown.

I type: application, press ctrl+z - the text is undone.
I press ctrl+y, nothing appears. Am i doing something wrong, so the
redo action doesn't work?

I am using, as you can see PyQt 4.4.4 and python 2.5.2. Upgrading
isn't that easy (on Gentoo I have to upgrade also portage and umask a
few packages), so I would like to first know, if that might be problem
and whether I should upgrade.

-- 
Filip Gruszczyński