Haven't yet had a chance to take a thorough look at this.
I inserted the following near the beginning of your script:

use Inline C => Config =>
  BUILD_NOISY => 1;

That way you get to see any compiler warnings that are emitted during the C compilation, and with my cc-4.5.2 build of perl-5.14 I saw:

try_pl_f4a3.xs: In function 'get_proc_name':
try_pl_f4a3.xs:35:1: warning: function returns address of local variable
try_pl_f4a3.xs: In function 'process_list':
try_pl_f4a3.xs:57:5: warning: passing argument 2 of 'Perl_newRV' from incompatible pointer type
C:\MinGW\perl\lib\CORE/proto.h:2567:19: note: expected 'struct SV * const' but argument is of type 'struct AV *'

Whether there's anything relevant there, I don't know.

I get different output to you, of course. But in the middle of the output I also got one odd-looking line:

1348┤aæ☻↑:ñ $   ↑:ñ  ~↑☻

When I switched to a gcc-3.4.5 build of perl-5.12, I found out what 1348 really was:
1348TomTomHOMERunner.exe

But then I got a strange line at the beginning of the output:

4ð¬─w4§Å ↑
whereas, with gcc-4.5.2, that had been:
4<unknown>