you posted this question in the SD Section not HD section, i take it you have an HD box what satellite and channels are you talking about,have you manually scanned the satellite or added pet settings ????
download the new satellite xml for 28.2 east below unzip and ftp it to the etc/ folder and overwrite your own then reboot then rescan
some image the satellite.xml file could be in usr/etc/tuxbox just overwrite then reboot and scan afterwards,if it dont find all the channels afterwards your dish is out or there is something up with your tunner