as ej said, use the "set $1" message. this is the same in many cases where you want to have visual feedback *back* to an object after a number comes out (like if you want a slider to go into a number box, but changing the number box also sets the slider level). Without "set" in the loop, you’re choosing a umenu number, it goes into the preset and selects it, the preset sends the number out into the umenu, it sends it back into preset, etc… not allowed. Put "set $1" between preset and umenu so that the umenu actually selects the preset (which is the overall goal) but when you click a preset, it will only *set* the umenu selection.
Also, umenu counts from 0, but preset counts from 1, so you will need to use +1 and -1 respectively.
