[racket] struct in racket

I don't know if I did something wrong or not, but this seems strange to me.

Using #lang racket, in the interaction window from DrRacket (DrRacket,
version 5.0.1, english by PLT),

> (struct posn (x y))
> (struct? (posn 3 4))
#f
> (struct-info? (posn 3 4))
#f
#t
>

So (posn 3 4) is not a struct in racket? The same goes for define-struct.
But

> (struct-constructor-procedure? posn)
#t
>

Usually how people define structure in Racket?

Cheers,
Frodo
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.racket-lang.org/users/archive/attachments/20100906/88203360/attachment.html>