Autoflush and XS

[Sisyphus]

Hi,
Consider the following Inline C script:
use warnings;
use Inline C => <<'EOC';
void func_1() {
     printf("SOMETHING");
     }
void func_2() {
     printf("something\n");
     }
EOC
#$| = 1; #makes no difference
print "1\n";
func_1();
print "\n2\n";
func_2;
print "3\n";
__END__
With perl 5.8.4 I would expect that to produce the following output:
1
SOMETHING
2
something
3
And that's exactly what is produced for me on Win32. But on my MDK-9.1 
Linux I'm getting:
1

2
SOMETHINGsomething
3
So the question is: How do I get the expected result without altering 
the C code ?

The actual XS file that Inline generates is included below (if that helps).
Note that the problem is _not_ specific to Inline C. I've simply written 
it that way for simplicity, hoping that someone else can readily 
replicate the unusual result and maybe point to a solution. In "real 
life" I'm dealing with a third party library in a normal XS-build 
environment - and getting that odd behaviour with a function (within 
that library) that prints to stdout but doesn't print a newline.

Cheers,
Rob
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
#include "INLINE.h"
void func_1() {
     printf("SOMETHING");
     }
void func_2() {
     printf("something\n");
     }
MODULE = try_pl_903a        PACKAGE = main
PROTOTYPES: DISABLE
void
func_1 ()
        PREINIT:
        I32* temp;
        PPCODE:
        temp = PL_markstack_ptr++;
        func_1();
        if (PL_markstack_ptr != temp) {
          /* truly void, because dXSARGS not invoked */
          PL_markstack_ptr = temp;
          XSRETURN_EMPTY; /* return empty stack */
        }
        /* must have used dXSARGS; list context implied */
        return; /* assume stack size is correct */
void
func_2 ()
        PREINIT:
        I32* temp;
        PPCODE:
        temp = PL_markstack_ptr++;
        func_2();
        if (PL_markstack_ptr != temp) {
          /* truly void, because dXSARGS not invoked */
          PL_markstack_ptr = temp;
          XSRETURN_EMPTY; /* return empty stack */
        }
        /* must have used dXSARGS; list context implied */
        return; /* assume stack size is correct */