mutator internal error (doesn't like literal numbers?)

[robby]

This program (with the mutator below):

#lang planet plai/plai:1:12/mutator
(allocator-setup "no-collection-collector.ss" 100)
(cons 4 #t)

produces the error:

Welcome to DrScheme?, version 4.2.4.2-svn3feb2010 [3m].
Language: planet plai/plai:1:12/mutator custom; memory limit: 256 megabytes.
. . ?: Bug in the PLAI Mutator framework; unrecognized form 4 in: 4

This mutator is broken, but it passes the contract checks enough for the above program to fail.

#lang planet plai/plai:1:8/collector

(define ptr 0)

(define (init-allocator) (void))

(define (gc:deref loc) #f)
(define (gc:alloc-flat hv) (void))
(define (gc:cons hd tl) 0)
(define (gc:first pr) 0)
(define (gc:rest pr) 0)
(define (gc:flat? loc) #f)
(define (gc:cons? loc) #f)
(define (gc:set-first! pr new) (void))
(define (gc:set-rest! pr new) (void))

[robby]

lowered the priority because it works fine in 4.2.3