"not a procedure" problem on Windows

[khardy]

Some of the example code from the docs produce a "not a procedure" problem on windows.

For example the code below produces (highlighting lpf/dynamic in DrRacket?):

application: not a procedure;

expected a procedure that can be applied to arguments

given: #<network/s>
arguments...:

#<procedure:control>
#<procedure:sawtooth>

Similar issue results on using sine-wave.

Example program from docs pro

#lang racket/base

(require (planet clements/rsound:4:4))
(require (planet clements/rsound:4:=4/filter))

(define (control f) (+ 0.5 (* 0.2 (sin (* f 7.123792865282977e-005)))))
(define (sawtooth f) (/ (modulo f 220) 220))

(play (signal->rsound 88200 (lpf/dynamic control sawtooth)))