Odd output with 5.16.0, x86-64int architecture

Hi,

Here's the demo (Inline::C) script:

###################################
use warnings;
use Config;
use Math::MPFR qw(:mpfr);

use Inline C => Config =>
    CCFLAGS => "-D__USE_MINGW_ANSI_STDIO=1 " . $Config{ccflags},
    BUILD_NOISY => 1;

use Inline C => <<'EOC';

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

void check(char * in, SV * digits) {
     dXSARGS;
     long double ld;
     char *ptr, *buffer;;

     ld = strtold(in, &ptr);

     buffer = malloc(32 * sizeof(char));
     sprintf(buffer, "%.*Le", SvUV(digits) - 1, ld);
     ST(0) = sv_2mortal(newSVpv(buffer, 0));
     free(buffer);
     XSRETURN(1);

}

EOC

print check('1e-37', 18), "\n";
###################################

For both the x86 and x64 builds of Strawberry Perl-5.16.0 that script 
correctly outputs:
1.00000000000000000e-037

But for the x86-64int build of Strawberry Perl-5.16.0 I'm getting:
-0.00000000000000000e+000

Does anyone see a reason for this anomalous behaviour with the x86-64int 
build ?
I get precisely the same output with an x86-64int perl-5.16.0 that I built 
using mingw.org's gcc-4.5.2.

Here's the 'perl -V' of the problem Strawberry Perl:

####################################
Summary of my perl5 (revision 5 version 16 subversion 0) configuration:

  Platform:
    osname=MSWin32, osvers=4.0, archname=MSWin32-x86-multi-thread-64int
    uname='Win32 spp-spec-64int 5.16.0.1 #1 Tue May 22 21:03:41 2012 i386'
    config_args='undef'
    hint=recommended, useposix=true, d_sigaction=undef
    useithreads=define, usemultiplicity=define
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=undef
    use64bitint=define, use64bitall=undef, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='gcc', ccflags 
=' -s -O2 -DWIN32  -DPERL_TEXTMODE_SCRIPTS -DPERL_IMPLICIT
_CONTEXT -DPERL_IMPLICIT_SYS -fno-strict-aliasing -mms-bitfields',
    optimize='-s -O2',
    cppflags='-DWIN32'
    ccversion='', gccversion='4.6.3', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=12345678
    d_longlong=undef, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long long', ivsize=8, nvtype='double', nvsize=8, Off_t='long 
long',
lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='g++.exe', ldflags 
='-s -L"C:\_32\strawberry516_64int\perl\lib\CORE" -L"C
:\_32\strawberry516_64int\c\lib"'
    libpth=C:\_32\strawberry516_64int\c\lib 
C:\_32\strawberry516_64int\c\i686-w6
4-mingw32\lib
    libs=-lmoldname -lkernel32 -luser32 -lgdi32 -lwinspool -lcomdlg32 -ladvapi32
 -lshell32 -lole32 -loleaut32 -lnetapi32 -luuid -lws2_32 -lmpr -lwinmm -lversion
 -lodbc32 -lodbccp32 -lcomctl32
    perllibs=-lmoldname -lkernel32 -luser32 -lgdi32 -lwinspool -lcomdlg32 -ladva
pi32 -lshell32 -lole32 -loleaut32 -lnetapi32 -luuid -lws2_32 -lmpr -lwinmm -lver
sion -lodbc32 -lodbccp32 -lcomctl32
    libc=, so=dll, useshrplib=true, libperl=libperl516.a
    gnulibc_version=''
  Dynamic Linking:
    dlsrc=dl_win32.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
    cccdlflags=' ', 
lddlflags='-mdll -s -L"C:\_32\strawberry516_64int\perl\lib\C
ORE" -L"C:\_32\strawberry516_64int\c\lib"'


Characteristics of this binary (from libperl):
  Compile-time options: HAS_TIMES HAVE_INTERP_INTERN MULTIPLICITY
                        PERLIO_LAYERS PERL_DONT_CREATE_GVSV
                        PERL_IMPLICIT_CONTEXT PERL_IMPLICIT_SYS
                        PERL_MALLOC_WRAP PERL_PRESERVE_IVUV PL_OP_SLAB_ALLOC
                        USE_64_BIT_INT USE_ITHREADS USE_LARGE_FILES
                        USE_LOCALE USE_LOCALE_COLLATE USE_LOCALE_CTYPE
                        USE_LOCALE_NUMERIC USE_PERLIO USE_PERL_ATOF
  Built under MSWin32
  Compiled at May 22 2012 21:11:55
  %ENV:
    PERL_JSON_BACKEND="JSON::XS"
    PERL_YAML_BACKEND="YAML"
  @INC:
    C:/_32/strawberry516_64int/perl/site/lib
    C:/_32/strawberry516_64int/perl/vendor/lib
    C:/_32/strawberry516_64int/perl/lib
    .
####################################

Cheers,
Rob