Hi everyone! 

Here is the source code:

(define cc #f)
(begin (call/cc (lambda(k) (set! cc k))) (display "Will you catch me?\n"))
(cc)

In newest Racket, (cc) => nothing
In newest Chez/Ypsilon (cc) => Will you catch me?\n

I asked an expert about this, and he said that Chez/Ypsilon is right.

Then I post a bug report to Racket, Matthew Flatt said 
[R6RS isn't clear on the point of splicing `begin's or 
on the continuation of a module body.]

Then I checked r7rs-small-draft-9, I believe there is some ambiguity here.
What do you think about this problem? 
Actually I am a Scheme newbie, I apologize if this problem doesn't make any sense.