PLEASE READ THIS WHEN THE SET BUTTON DOESN'T WORK FOR YOU
I know now why SET doesn't work for some people. It depends on your setting in the custom functions what SET should do. (custom function 1)
on setting 0: Normal it does nothing, ALSO IN THE INFO MENU
on settings 1, 2 and 3 it works
on setting 4: AF frame select it selects AF frames, ALSO IN THE INFO MENU
If you have setting 0, I recommend changing to 1,2 or 3.
If you have setting 4 I suppose you want to keep the AF frame selection on this button, so build yourself an autoexec.bin that uses PLAY button instead. downside: the function that is usually on the PLAY button won't be available (increase number of pictures taken by time-lapse by one)
I will set this function to another button soon so you can use settings 0 and 4 and still have the full functionality of the hack.