I have my C-band lnb connected to port A(0Khz) and Ku-band lnb connected to port B(22Khz). I installed the tbs 6920 driver v1.0.5.0 and my channels on C-band work but none of my channels on Ku-band work. I rolled back the driver to v1.0.4.1 and both my C-band and my Ku-band channels work.