problems evaluating code depending on version

[Stefan Israelsson Tampe]

hi,

I'm trying to use this as a way to defined different versions of the code depending on the 
guile-version. So here it is,



(eval-when (compile load eval)
  (define (ver)
    (let ((v (version)))
      (cond
       ((string-match "^2.0" v)
        'v2.0)
       ((string-match "^2.1" v)
        'v2.1)
       (else #f)))))

(define-syntax guile-stuff
  (lambda (x)
    (syntax-case x ()
      (_
       (let ((q (ver)))
         (cond
          ((eq? q 'v2.0)
           #'(begin 1))
          ((eq? q 'v2.1)
           #'(begin
               (define-syntax-rule (fluid-let-syntax . l)
                 (syntax-parametrize . l))
               (export fluid-let-syntax)))
          (else (error "not supported version"))))))))

(guile-stuff)

This does not work in master (v2.1) why?
/Stefan