Hello, i already notice this issue before, but now i've made an example to prrove what i say.
Here : http://www.megaupload.com/?d=MQM1R8TG
for a zip file or here : http://www.megaupload.com/?d=8JIH1V15
for the .reason file.
You can download a Reason 6 project, with only one Kong Device :
On this Kong, 4 pads with the same Bass drum sound.
Pad 1 and pad 5 ( named resp BD1 Link grp and BD2 Link grp ) linked with Mute Group "D"
Pad 2 and pad 6 ( named DB Gatein->Gateout and BD2 Gatein->Gateout ) linked with the backpanel gate in/out connectors.
Personnaly, i think that the 1st layer Pad1 and Pad5 ( play it by click only on Pad1 )act as expected, the two sound are in sync, no phasing problems. But when i click on the Pad2 to play Pad2 and Pad6 simultaneously, the output isn't the same, there is something wrong, the sound is "ugly" there is a sort of phasing problem, strange random high pitch noise...