MOP bug?

[Michael Burschik]

If I call guile interactively and type this:

(use-modules (oop goops))
(define-class <thing> () (slot1))
(define-method (slot-unbound (c <class>) (o <thing>) s)
(display "You can't do that.\n"))
(define mything (make <thing>))
(slot-ref mything 'slot1)

I get what I want. If I put the above statements in a file and execute guile 
-f file or guile -s file, I get this error message:

ERROR: In procedure class-direct-methods:
ERROR: Wrong type argument in position 1: #<struct 40209640:40209640>

Now why should that be?

I am using guile 1.4, goops 1.0.2 and linux 2.4.

Regards

Michael Burschik