As nobody came with any help I will tell my story about the saa7134 card I have.
Having no sound with it I searched the internet. More people had similar problems, but solutions were not abundant. The saying goes that Kdetv has no maintainer anymore. People were told to use other products.
I immediately tried your modprobe and then your mplayer statement. It works. I do not understand all the options you give to mplayer, but after some trial I could mplayer let do scanning (it found 11 channels) and found out how to call mplayer to show such a channel.
This all is of course not of any help to you, but I must thank you for providing useful information to me. At least I can view TV now and with some script programming I will make an interface to call mplayer from the GUI with the right parameters