Hmmm just looked at the 605's manual and it appears the shop is correct - for some reason the 605 will only apply Pro Logic IIx to stereo PCM sources, not to multichannel ones (though it will happily apply it to multichannel Dolby Digital, dts and their HD equivalents). The 606 isn't listed on their site yet so think we'll have to wait till some review units start arriving before we'll know if the new model is still limited in this way.