I'm running Slackware 14.1 x86_64 with an Nvidia chip 660GTX on a laptop with Nvidia drivers 331.20 and Openbox 3.5.2 and the SpaceFM 0.9.3 file manager.
I noticed that if I open the SpaceFM file manger and click on a video and launch smplayer this way, the close button for the window in the upper right, if I click to close smplayer it will not close the application. Then it freezes and I have to keep clicking the close button in the upper right until I get a popup that asks if I'd like to terminate it.
If I go to 'Open' - 'Quit' smplayer always closes this way, but the close buttons on the upper right of the window don't always close smplayer.
I've tried the smplayer-0.8.6.tar.bz2 source listed on smplayer.sourceforge.net/en/downloads and I've compiled smplayer from source; 0.8.6 r6052, both have this same problem.
In Openbox I've tried switching themes, thinking this might be the problem, I've also tried clicking on and playing several video formats to test; avi, mp4, mkv, m4v, all with the same results.
I've also tried using different video preferences; xv, gl, vdpau, none of these have any change either...
I'm lost, nothing I try fixes this, there is a definite bug here with trying to get smplayer to constantly close using the windows close button.
I hope this can be fixed soon, I personally close apps this way, I find it quicker, then going through the file menu...