Easytag 1.99.12 builds and functions (apparently) correctly on x86 using the easytag-1.99.11 ebuild. Also consider patching media-libs/id3lib with the patching included in easytag upstream for proper unicode support.
*easytag-1.99.12 (14 Apr 2006) 14 Apr 2006; Daniel Drake <dsd@gentoo.org> -easytag-1.99.7.ebuild, -easytag-1.99.10.ebuild, +easytag-1.99.12.ebuild: Version bump thanks to Pietro Franchi in bug #129741