[plt-scheme] problems (with PLAI Scheme) on 4.2.4

Hi,

I realized (unfortunately, during the classroom) that there is a problem with PLAI Scheme on 4.2.4.

With 4.2.1:

(define-type Foo
  (foo (x number?)))
(foo 1)
--> (foo 1)

With 4.2.4:

(define-type Foo
  (foo (x number?)))
(foo 1)
--> (make-foo1 1)

ie. the nice abstractions provided by define-type are revealed naked. Embarrassing!

Is this a known bug? (I would refuse to call that a feature ;))

I also found that 4.2.4 tends to freeze a lot, and even crash (I'm on mac os 10.6), whereas this simply never happened to me with 4.2.1. I can't tell if that's related to PLAI Scheme or not, though.

Any idea of what can be going wrong? My installation of 4.2.4 and PLAI Scheme is just "fresh", recently downloaded and installed both.

In the meantime, I'm will be sticking to 4.2.1.

Thanks!

-- Éric