[plt-scheme] using swindle within a module

I am trying to wrap some simple swindle code in a module

(module beliefs mzscheme
  (require (lib "swindle.ss" "swindle"))

  (defclass test ()
    (h :initializer (lambda () (make-hash-table))
        :accessor h))

  (provide test)
)


but evaluation of this code gives:

Welcome to DrScheme, version 350.
Language: Pretty Big (includes MrEd and Advanced Student).
module: identifier already imported (from a different source) in: set!-values
>

I would be grateful for any help

Cheers

Chris