Body of `begin' is not evaluated in left-to-right order?

[Kaloian Doganov <kaloian at doganov dot org>]

Hello!

I am new to Kawa and Scheme and I'm going through various tutorials,
trying to learn the language.  I've just encountered a behaviour in Kawa
that seems unusual to me.  Here is the example:

(define (sleep-example)
		(begin (display "before\n") (sleep 3) (display "after\n")))

The obvious goal is to write a procedure that displays a line, then
waits for some time (3 seconds) and displays another line.  When I
evaluate `(sleep-example)' in Kawa, it first waits for 3 seconds, and
then prints the both lines immediately one after another.  The behaviour
looks just like if the body of `sleep-example' was:
   
(begin (sleep 3) (display "before\n") (display "after\n")))

The same example evaluated in Guile works as expected - "before" is
displayed at once, then "after" is displayed 3 seconds later.  Am I
missing something, or this is bug in Kawa?

I am using Kawa 1.8 and Guile 1.6.7 on a GNU system.