Yesterday I bought a wireless Samsung keyboard for my ES8000 smart tv. The keyboard (VG-KBD1500) works fine, but it wont switch the channels. If I use my TV remote (samsung universal remote that came with the TV), I can switch the channels on my cable set top box. Why the keyboard can't do the same? Is there something that I can do to make it work, or the keyboard can only switches the channels if the channel source is DVB-T or DVB-C?