Both of the new BTN hd alt. channels are in my guide (218-1 & 219-1). However, I am getting "searching for satellite 771" messages on both of my H20-600 receivers. BTN 220 hd is fine, as are the alternate sd channels. All signal strengths on 103b are mid to upper 90s. Also all other hd channels are fine. Any suggestions as to what is wrong? Thanks.