The ebuild for gcc 3.3.6 tries to download 'bounds-checking-gcc-3.3.6-1.00-r1.patch.bz2' from the SourceForge mirrors. This file does not exist, the project 'boundschecking' has only released 'bounds-checking-gcc-3.3.6-1.00.patch.bz2'.
it's on the Gentoo mirrors
But the ebuild tries to download it from SourceForge, where it's not.
portage fetches everything from gentoo mirrors first