[plt-scheme] errors when using srfi-1

Hello all

I found one bug in srfi in plt206

I have code (compatibility mode for our porgramms):
----------------------------------------------------------------------
(module a mzscheme
  (require 
   (lib "13.ss" "srfi")
   (lib "1.ss" "srfi")
   )
  (provide
   (all-defined)
   )

  ;; Return string that is concatination of 'list' items seperated by 'sep'.
  ;; alias for srfi-13
  (define join-fields string-join)

  ;; Return list of items of list satisfying pred.
  ;; alias for function from srfi-1
  (define collect-if filter)

  ;; like collect-if but collects what pred returns
  ;; alias for function from srfi-1
  (define collect-iff filter-map)

  ) ; end of module

(require a)
----------------------------------------------------------------------

but when i load it with (load "a.scm") i get message:

a.scm:6:2: module: identifier already imported (from a different source) at: reverse! in: (require (lib "13.ss" "srfi") (lib "1.ss" "srfi"))

same errors i get when i try use schemeunit from schematics, that also use
srfi-1 

-- 
With best wishes, Alex Ott
Jet Infosystems,       http://www.jetinfosoft.ru/
                       +7 (095) 411 76 01