missing channels,lnb or receiver, too far north

hello i have a echostar 2110 ,version 400 software,,80cm dish,old sky annaloge universal lnb,pointed to hotbirdlive north of Belfast N.I., the problem is at 11900 i recieve vox then no channels until i reach 12245 c5dtt i recieve all the rest of the channels ok it just picks up nothing between 11900-12245,the signal strength falls away,also when i try to do a ota upgrade it fails every time even though i seem to get good signal strength,could anyone tell me what i could try to sort these problems out ,thanks very much,trevor.