cant get some channels on 28.2, tm9100 super

[aj1soad]

hi all. ive got a tm9100 super, 90cm triax dish and lnb. ive scanned the 28.2 satelite and i cant get the bbc or itv channels, but good signal with channel 4,scuzz etc. i took my box to my dads house and searched for channels with his sky dish and it picked up all the itv channels and bbc channels. so i took it back home and conected everything back up, all the channels are still there but no picture. there is just a big ! at the start of each channels name. any ideas whats wrong?