I have the option "Start videos in fullscreen" enabled in SMPlayer. Sometimes when I start a video, I know in advance that I rather would like to use SMPlayer in window mode. So I press "f" to exit fullscreen mode, shortly after the SMPlayer window appeared and playback started.
This often leads to the effect that after the fullscreen mode is left, the floating control is still available - so I then have two control bars (see screenshot). The auto-hide mechanism thereby remains active, so mouse movements within the SMPlayer window shows the control for some seconds, until it hides. The control hides in general only after I enter and again leave fullscreen mode (e.g. by pressing "f" twice).
SMPlayer version: SVN revision 6971
OS: Ubuntu Linux 14.04 Mint AMD64
This was fixed (or at least it would be more unlikely to happen) in version svn r6979.
This works for me, thank you!