I just came across this question as a consequence of definitely establishing that triggers on sheet-activation don't work in the Browser (official from QlikTech) - it does work, though, on buttons - the underlying logic is somehow different.
Now, I have been told that, although the buttons are all linked "from left to right" across all the sheets, Qlikview does not duplicate any triggers laid on a button - but it seems that under certain circumstances it does.
I don't know these, so I had to do it manually and it is a terrible thing to do, "clicking up" approx. four triggers per button, on approx. eight buttons, across approx. eight sheets...
Thanks a lot!