[plt-scheme] Analyze error I don't grok

MJ Ray wrote:
>Start DrScheme, select R5RS as the language level and enter the code:
>
>(define lst
>  (lambda (n)
>    (if (<= n 0)
>        '()
>        (cons n (lst (- n 1))))))
>
>into the editor.  Click "Analyze".  It goes red.  Right-click the red and
>pick "Show Errors" -- why does it give that error?

Nothing goes red for me.  What kind of error do you get?  On which
platform?

Philippe