Version: (using KDE KDE 3.5.3) Open any video (divx/xvid), press several times right-arrow, after a while the playback is sort of frozen -- you cannot do anything with program (with mouse or keyboard), but the program still plays (audio + video). However, the only thing the user can do is to kill it.
I come across the same issue or similar one. In my case, UI hangs only when playing video with subtitles otherwise everything works well. See: http://bugs.kde.org/show_bug.cgi?id=136091
Also video + subtitles, I just forgot to mention it :-)
*** Bug 136091 has been marked as a duplicate of this bug. ***
*** This bug has been marked as a duplicate of 118364 ***