firstof on Padobjects

Hello,

is firstof(x) working differently on padobjects than on switch objects.
I have 1x16 pad Object and want to use the firstof(x) function to get the pad pressed but it doesnt seem to work.

padpressed=firstof(x);
MultiSlider.x[padpressed]+=incdec1;

What is weird is that when i slide over all 16 pads the monitor shows the right value for the padpressed but when i press a single one i dont get a value.

Any insights to this?