Have you noticed the transparent screen of smplayer when you are using compiz and maybe cairo-dock? Well it’s ridiculous that when you open your videos using SMplayer you can just hear audio and no video! Here’s how you fix this:

sudo bash -c “cat > /usr/bin/smplayer.helper” <<EOF
exec smplayer.real “\$@”

sudo chmod 755 /usr/bin/smplayer.helper
sudo mv /usr/bin/smplayer{,.real}
sudo ln -sf smplayer.helper /usr/bin/smplayer

If you don’t use sudo then just use “su” to login as root and do the above!

Good luck!