perl -V and perl -v do two different things. (note the capitalization on the V)

Here's what capital V does on my main Strawberry 5.10.0.4 installation:

Summary of my perl5 (revision 5 version 10 subversion 0) configuration
+:
  Platform:
    osname=MSWin32, osvers=5.1, archname=MSWin32-x86-multi-thread
    uname=''
    config_args='undef'
    hint=recommended, useposix=true, d_sigaction=undef
    useithreads=define, usemultiplicity=define
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=und
+ef
    use64bitint=undef, use64bitall=undef, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='gcc', ccflags =' -s -O2 -DWIN32 -DHAVE_DES_FCRYPT  -DPERL_IMPL
+ICIT_CONTEXT -DPERL_IMPLICIT_SYS -fno-strict-aliasing -DPERL_M
SVCRT_READFIX',
    optimize='-s -O2',
    cppflags='-DWIN32'
    ccversion='', gccversion='3.4.5', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=undef, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='long lo
+ng', lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='g++', ldflags ='-s -L"C:\strawberry\perl\lib\CORE" -L"C:\straw
+berry\c\lib"'
    libpth=C:\strawberry\c\lib
    libs= -lmsvcrt -lmoldname -lkernel32 -luser32 -lgdi32 -lwinspool -
+lcomdlg32 -ladvapi32 -lshell32 -lole32 -loleaut32 -lnetapi32 -
luuid -lws2_32 -lmpr -lwinmm -lversion -lodbc32 -lodbccp32
    perllibs= -lmsvcrt -lmoldname -lkernel32 -luser32 -lgdi32 -lwinspo
+ol -lcomdlg32 -ladvapi32 -lshell32 -lole32 -loleaut32 -lnetapi
32 -luuid -lws2_32 -lmpr -lwinmm -lversion -lodbc32 -lodbccp32
    libc=-lmsvcrt, so=dll, useshrplib=true, libperl=libperl510.a
    gnulibc_version=''
  Dynamic Linking:
    dlsrc=dl_win32.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
    cccdlflags=' ', lddlflags='-mdll -s -L"C:\strawberry\perl\lib\CORE
+" -L"C:\strawberry\c\lib"'


Characteristics of this binary (from libperl):
  Compile-time options: MULTIPLICITY PERL_DONT_CREATE_GVSV
                        PERL_IMPLICIT_CONTEXT PERL_IMPLICIT_SYS
                        PERL_MALLOC_WRAP PL_OP_SLAB_ALLOC USE_ITHREADS
                        USE_LARGE_FILES USE_PERLIO
  Built under MSWin32
  Compiled at Jan 29 2009 20:56:38
  @INC:
    C:/strawberry/perl/lib
    C:/strawberry/perl/site/lib
    .
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int main (void) {
    return 0;
}
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gcc -o try.exe try.c -v
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Oh, cap 'V,' yep didn't pick up on that. Alright, perl -V gives me:

Summary of my perl5 (revision 5 version 10 subversion 0) configuration
+:
  Platform:
    osname=MSWin32, osvers=5.1, archname=MSWin32-x86-multi-thread
    uname=''
    config_args='undef'
    hint=recommended, useposix=true, d_sigaction=undef
    useithreads=define, usemultiplicity=define
    useperlio=define, d_sfio=undef, uselargefiles=define, usesocks=und
+ef
    use64bitint=undef, use64bitall=undef, uselongdouble=undef
    usemymalloc=n, bincompat5005=undef
  Compiler:
    cc='gcc', ccflags =' -s -O2 -DWIN32 -DHAVE_DES_FCRYPT  -DPERL_IMPL
+ICIT_CONTEXT -DPERL_IMPLICIT_SYS -fno-strict-aliasing -DPERL_MSVCRT_R
+EADFIX',
    optimize='-s -O2',
    cppflags='-DWIN32'
    ccversion='', gccversion='3.4.5', gccosandvers=''
    intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234
    d_longlong=undef, longlongsize=8, d_longdbl=define, longdblsize=12
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='long lo
+ng', lseeksize=8
    alignbytes=8, prototype=define
  Linker and Libraries:
    ld='g++', ldflags ='-s -L"C:\strawberry\perl\lib\CORE" -L"C:\straw
+berry\c\lib"'
    libpth=C:\strawberry\c\lib
    libs= -lmsvcrt -lmoldname -lkernel32 -luser32 -lgdi32 -lwinspool -
+lcomdlg32 -ladvapi32 -lshell32 -lole32 -loleaut32 -lnetapi32 -luuid -
+lws2_32 -lmpr -lwinmm -lversion -lodbc32 -lodbccp32
    perllibs= -lmsvcrt -lmoldname -lkernel32 -luser32 -lgdi32 -lwinspo
+ol -lcomdlg32 -ladvapi32 -lshell32 -lole32 -loleaut32 -lnetapi32 -luu
+id -lws2_32 -lmpr -lwinmm -lversion -lodbc32 -lodbccp32
    libc=-lmsvcrt, so=dll, useshrplib=true, libperl=libperl510.a
    gnulibc_version=''
  Dynamic Linking:
    dlsrc=dl_win32.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
    cccdlflags=' ', lddlflags='-mdll -s -L"C:\strawberry\perl\lib\CORE
+" -L"C:\strawberry\c\lib"'


Characteristics of this binary (from libperl):
  Compile-time options: MULTIPLICITY PERL_DONT_CREATE_GVSV
                        PERL_IMPLICIT_CONTEXT PERL_IMPLICIT_SYS
                        PERL_MALLOC_WRAP PL_OP_SLAB_ALLOC USE_ITHREADS
                        USE_LARGE_FILES USE_PERLIO
  Built under MSWin32
  Compiled at Jan 29 2009 20:56:38
  @INC:
    C:/strawberry/perl/lib
    C:/strawberry/perl/site/lib
    .
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I am running on windows XP and I am pretty sure our office is up to using SP3. I can double check on that though if you need those details. Running the gcc command on try.c, as you described, yields:

Reading specs from C:\GNAT\lib\gcc-lib\pentium-mingw32msv\2.8.1\specs
gcc version 2.8.1
 C:\GNAT\lib\gcc-lib\pentium-mingw32msv\2.8.1\cpp.exe -lang-c -v -unde
+f -D__GNUC__=2 -D__GNUC_MINOR__=8 -Di386 -D_WIN32 -DWIN32 -D__WIN32__
+ -D__MINGW32__ -DWINNT -D_X86_=1 -D__STDC__=1 -D__stdcall=__a
ttribute__((__stdcall__)) -D__cdecl=__attribute__((__cdecl__)) -D__i38
+6__ -D_WIN32 -D__WIN32__ -D__WIN32__ -D__MINGW32__ -D__WINNT__ -D_X86
+_=1 -D__STDC__=1 -D__stdcall=__attribute__((__stdcall__)) -D_
_cdecl=__attribute__((__cdecl__)) -D__i386 -D__WIN32 -D__WINNT -Asyste
+m(winnt) -Acpu(i386) -Amachine(i386) -remap -Di386 -Di586 -Asystem(un
+ix) -Acpu(i386) -Amachine(i386) -D__i386__ -D__i586__ -Asyste
m(unix) -Acpu(i386) -Amachine(i386) try.c C:\DOCUME~1\BJACKS~1.SLC\LOC
+ALS~1\Temp\cca00264.i
GNU CPP version 2.8.1 (80386, BSD syntax)
#include "..." search starts here:
#include <...> search starts here:
 C:\GNAT\lib\gcc-lib\pentium-mingw32msv\2.8.1\include
End of search list.
 C:\GNAT\lib\gcc-lib\pentium-mingw32msv\2.8.1\cc1.exe C:\DOCUME~1\BJAC
+KS~1.SLC\LOCALS~1\Temp\cca00264.i -quiet -dumpbase try.c -version -o 
+C:\DOCUME~1\BJACKS~1.SLC\LOCALS~1\Temp\cca00264.s
GNU C version 2.8.1 (pentium-mingw32msv) compiled by GNU C version 2.8
+.1.
 as -o C:\DOCUME~1\BJACKS~1.SLC\LOCALS~1\Temp\cca002641.o C:\DOCUME~1\
+BJACKS~1.SLC\LOCALS~1\Temp\cca00264.s
 ld -o try.exe C:\GNAT\lib\gcc-lib\pentium-mingw32msv\2.8.1\crt2.o -LC
+:\GNAT\lib\gcc-lib\pentium-mingw32msv\2.8.1 -LC:\GNAT\lib -LC:\GNAT\l
+ib C:\DOCUME~1\BJACKS~1.SLC\LOCALS~1\Temp\cca002641.o -lmingw
32 -lgcc -lmoldname -lmsvcrt -lkernel32 -ladvapi32 -lshell32 -lmingw32
+ -lgcc -lmoldname -lmsvcrt
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It looks like I have a version of gcc installed from my GNAT development environment that might be conflicting with the one installed with strawberry perl. Does that sound right? Does that even matter?

Thank you again for all the help =)

Cheers.

It looks like I have a version of gcc installed from my GNAT development environment that might be conflicting with the one installed with strawberry perl.

Yes, that's not strawberry's gcc. Can you rename 'C:/GNAT' to 'C:/GNAT_hide' (so that the system can't find it), then re-run the CPAN install of Math::FFT. Hopefully the CPAN install will then work fine.

Then, assuming you do need that GNAT gcc, you just have to work out how to manage the co-existence of those 2 versions of gcc. Another way would be to make sure that C:/strawberry/c/bin is at the start of your path envvar whenever you want to use that version of gcc. To achieve that just run:

set PATH=C:\strawberry\c\bin;%PATH%
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That will ensure that strawberry's gcc is found instead of GNAT's. (You'll need to re-run that command every time you open up a cmd.exe shell that needs to find strawberry's gcc - unless you make that your permanent path setting.)

The best thing would be to remove the GNAT version, if possible.

Cheers,
Rob