Set up my amp to pass HDMI through on standby...correct?

[Tiggsy]

My Yamaha Amp allows me to set up the HDMI from ps3, 360, sky hf and apple TV to go to the tv if the amp is in standby...handy. But, it seems it will only do it for the last used input....i.e Run the PS3 through the amp with the amp on...turn off amp and ps3 will still work - but if i turn off the PS3 and turn on the xbox i have to turn on the amp, change input, and turn off again. This is ok (ish) as i can set up my harmony to do it....but does that sound right or shoudl it "detect" on HDMI signals somehow and switch itself?