Since version 16.6 the SMPlayer packages are built with Qt 5 by default.
However some users don’t like Qt 5 (for example the file open dialog is different) or there are bugs (for example in some versions of Qt 5 the numeric keypad keys don’t work as accelerators). For that reason now there’s available another PPA for Ubuntu with packages compiled with Qt 4.
To install packages from that PPA, first remove the normal PPA:
sudo add-apt-repository -r ppa:rvm/smplayer
Add the new one:
sudo add-apt-repository ppa:rvm/smplayer-qt4
Update and install:
sudo apt-get update sudo apt-get install smplayer smplayer-themes smplayer-skins