new warnings in 4.5a: bint expected, bignum provided

Hi.

I am seeing new (spurious?) warnings for the current unstable version (x86=
_64 and x32-ABI):

"bint" expected, "bignum" provided

A minimal example:

bugz11.scm:
=2D--
(module bugz11
  (export
   (list-ref-check::obj l pos::bint))
  (main main))

(define (list-ref-check l pos)
  (let iter ()
    (if (pair? l)
        (cond ((=3D pos 0)
               (car l))
          (else
            (set! l (cdr l))
            (set! pos (- pos 1))
            (iter)))
        #f)))

(define (main args)
  (let ((val (list-ref-check args 1)))
    (display val)
    (newline)
    0))
=2D--

 > bigloo -O3 -ldopt "-static" -o bugz11 bugz11.scm

File "bugz11.scm", line 14, character 370:
#            (set! pos (- pos 1))
#                      ^
*** WARNING: iter
Type error --  "bint" expected, "bignum" provided

Greetings
Sven