Hi Lutz,
(define (mouse-action id type x y button cnt mods)
(println "id:" id " type:" type " x:" x " y:" y " button:" button " count:" cnt " mods:" mods))
Should be ->
(define (mouse-action x y id type x y button cnt mods)
(println "id:" id " type:" type " x:" x " y:" y " button:" button " count:" cnt " mods:" mods))