PBS multiple language transmissions

[colbec]

Yesterday I was watching a motor show on a PBS channel that advertised that it was available (AC-3) in English and Spanish on the Coolsat 6000. Indeed, when I went to the audio settings there was audio channel 1 in English and channel 2 in Spanish. The problem was that on channel 2 I was getting both English and Spanish. Stereo/left/right of course was ineffective since this was AC-3 (so I guess this could be inactivated in software). Next time I see it I will see if I need to cancel out some speakers, but it seems that maybe the transmission was at fault here? Surely in this situation all a user would be expected to do is change the audio channel?