We have done several RTI/Kaleidescape combos via IP and have never had to change the sustain delay on remotes or inwalls. None have been zigbee and none have included the new bluray units, only K300 and K6000. Does it do it only when the remote first wakes up or always? It may be buffering the command somehow during the first second while the zigbee is connecting and then sending out more than you expected.