Sui, i'm not happy when overruling you :'(
but:
The trigger radius must cover both the unit detecting and the unit being detected for the trigger to activate. If only one of the units is inside the trigger, it won't go off.
If i remember correctly, it's just the unit to be detected,
who's required to be inside the trigger area.
I was using this at least one year ago, so shame on me
if i remember wrong now, but afaik it's just the unit to be
detected, referring to the trigger's_list.
~S~ CD