Help! i bought a new dish . i went with the slimline SWM 24x32 oval with 5 lbn's for HD. i cant get a signal! it keeps reading zero. do i have to have all new HD boxes? i"m trying to use my old tivo boxes for now and will up grade to the HD boxes next year when money permits. i know i will not get the HD siganl but i cant get anything at all!