The cite of "MingW64 version that I'm using to build Perl: mingw-w32-bin_i686-mingw_20111219.zip" in your post raises a suspicion, since the sourceforge page says:

The format is:
<Target>[-Version]-<Src/Bin>-<Host>[-Cygwin Version]_<Date Code>[_pers
+onal tag].[extension]
<Target>

"mingw-w32" or "mingw-w64"
The target is the binary format the tool chain will generate.
"mingw-w64" means the toolchain will generate 64bit binaries that will
+ run on windows natively (64bit windows required)
"mingw-w32" means the toolchain will generate 32bit binaries that will
+ run on windows natively
[download]

Is it possible you're using the wrong version? And why cite the zip archive rather than the code itself?