KPlayer does its best to not leave behind any MPlayer processes. However,
it does not always succeed. If MPlayer forks, one of the processes may
sometimes not exit. You have to kill it manually then.

Occasionally when starting playback, resizing the window or switching to
full screen mode the picture may not show up in the KPlayer window until
you resize it. If you can find a way to reproduce this consistently,
please let me know.

When KPlayer is minimized, and you start a new instance, the window is
restored, but it does not become activated and is the last one in the
Alt-Tab order. This is believed to be a KWin problem.

When playing an audio-only file KPlayer will resize its window to the
smallest height possible, however a small part of the video area will
still be visible. This may be construed to be a feature though. :-)

The progress slider thumb may jump back and forth when seeking. This
is a problem of KPlayer syncronization with MPlayer that should be
resolved in a future version.

Following are known MPlayer issues that affect KPlayer for which no
workaround have been found yet and that are not yet fixed in MPlayer.

- if any window or widget like a menu o tooltip pops up over the MPlayer
  window and then goes away, the MPlayer window will flicker with a nasty
  blue background;

- if playback is paused, any seek or volume command will unpause it, and so
  will pressing any Alt-Key combination when mplayer window has the focus;
  the latter will result in the pause action being in the wrong state;

- when MPlayer is paused or stopped, it may leave the last displayed frame
  in the window or replace it with a black background;

- seeking to absolute position does not work well on some movie types, in
  particular MPEG; you should use Forward/Backward commands in those cases.