gcc issue for generated code from OpenGL.xs

Hi,

I discover by building sdl-perl on ubuntu dapper and Debian Etch specific error with gcc 4.0.3 (ok with 4.1.1).
I know it's a bit harmless as upgrading gcc seems to "fix" the issue.

Regards.

---
Error:
cc -I/usr/lib/perl/5.8/CORE -fPIC -I./include -I/usr/include/SDL -I/usr/include/GL -I/usr/include/SDL -D_REENTRANT -DHAVE_GL -DHAVE_SDL -DHAVE_GLU -DUSE_THREADS -fPIC -c -D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -O2 -o SDL/OpenGL.o SDL/OpenGL.c
SDL/OpenGL.xs: Dans la fonction «XS_SDL__OpenGL_glPolygonStipple» :
SDL/OpenGL.xs:5631: attention : pointer targets in passing argument 1 of «glPolygonStipple» differ in signedness
SDL/OpenGL.xs: Dans la fonction «XS_SDL__OpenGL_glBitmap» :
SDL/OpenGL.xs:6119: attention : pointer targets in passing argument 7 of «glBitmap» differ in signedness
SDL/OpenGL.xs: Dans la fonction «XS_SDL__OpenGL_glPixelMap» :
SDL/OpenGL.xs:6214: attention : pointer targets in passing argument 3 of «glPixelMapuiv» differ in signedness
ExtUtils::Mkbootstrap::Mkbootstrap('SDL/OpenGL')

On ubuntu host:
Cible : i486-linux-gnu
Configuré avec: ../src/configure -v --enable-languages=c,c++,java,f95,objc,ada,treelang --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --program-suffix=-4.0 --enable-__cxa_atexit --enable-clocale=gnu --enable-libstdcxx-debug --enable-java-awt=gtk-default --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.4.2-gcj-4.0-1.4.2.0/jre --enable-mpfr --disable-werror --with-tune=pentium4 --enable-checking=release i486-linux-gnu
Modèle de thread: posix
version gcc 4.0.3 (Ubuntu 4.0.3-1ubuntu5)

on Debian host:
Cible : i486-linux-gnu
Configured with: ../src/configure -v --enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --program-suffix=-4.1 --enable-__cxa_atexit --enable-clocale=gnu --enable-libstdcxx-debug --enable-mpfr --with-tune=i686 --enable-checking=release i486-linux-gnu
Thread model: posix
gcc version 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)