your not adding the correct frequency for your muxes.
if you dont know them you could select a pre defined set of muxes to get you going.
to select these you do them whilst adding a network. you just have to select country, region etc
ive posted pics of what mine looks like as a idea (although i use DVB-S) and a picture of the pre defined section that should help.
Rob
also once you find your services make sure to either map all channels or just map the ones you want.