[plt-dev] Errors with SRFI-1 in R6RS mode that are not in #scheme mode in PLT 4.1.4.3-svn13feb2009

I am getting errors with SRFI-1 in R6RS mode that are not in #scheme mode in:

Welcome to DrScheme, version 4.1.4.3-svn13feb2009 [3m].

#lang scheme

(require (only-in srfi/1 split-at take drop))

(take '(a b c d e)  2) ; => (a b)
(drop '(a b c d e)  2) ; => (c d e)
(split-at '(a b c d e)  2) ; => expecting
                           ;(values (take '(a b c d e)  2) (drop '(a b
c d e)  2)

>(a b)
>(c d e)
>(a b)
>(c d e)

This does not:

#!r6rs

(import (rnrs base)
        (only (srfi :1) split-at take drop))

(take '(a b c d e)  2) ; => (a b)
(drop '(a b c d e)  2) ; => (c d e)
(split-at '(a b c d e)  2) ; => expecting
                           ;(values (take '(a b c d e)  2) (drop '(a b
c d e)  2)

>take: index 2 too large for list (not a proper list): {a b c d e}2
>drop: index 2 too large for list (not a proper list): {a b c d e}2
>take: index 2 too large for list (not a proper list): {a b c d e}2

What am I doing wrong?