Version: (using KDE 4.4.3) OS: Linux Installed from: Ubuntu Packages I think the changes done to the nsplugin part of konqueror in KDE SC 4.4.3 actually destroyed playback of all youtube-videos. For me all video stops before the end. Fx http://www.youtube.com/watch?v=T9jWX7wI9ns stops around 45 sec. KDE SC 4.4.2 did have flaws but at least it played to the end.
Could it be raleted to https://bugs.kde.org/show_bug.cgi?id=233434 and maybe this QT-bug http://bugreports.qt.nokia.com/browse/QTBUG-10809
I see the same with KDE 4.5 and trunk. I use the 32bit flash player now on 64bit, as the 64bit did not get released, but with the latest 64bit version I have around I see the same.
I can confitm this bug on KDE 4.6.1. Most youtube video's start fine, but stop at some point. (The progress bar goes to the end, but the playback doesnt)
Flash and Netscape plugins are no longer supported.