http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47460
--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-01-25 16:42:43 UTC --- My guess is that the Debian packages are built with --with-arch=i486 but your 4.4.5 build isn't (and your 4.5.1 build doesn't need to be as it's implied by the i686-pc-linux-gnu target)