dev-tex/tex4ht-20090611_p1038-r1 seems not to consider some small updates to hyperref.4ht, biblatex.4ht, and nameref.4ht (and no other files) that would be installed in TeX Live. See http://tug.org/tex4ht/. I am having troubles converting a LaTeX document to HTML using tex4ht because of those missing small updates (more specifically, in the biblatex.4ht)
Created attachment 303509 [details, diff] tex4ht-texmf-updates.patch patch with some differences between the original tex4ht files and the ones delivered with TeX Live.
Created attachment 303511 [details, diff] tex4ht-ebuild.patch Changes to the original ebuild.
+*tex4ht-20090611_p1038-r2 (18 Feb 2013) + + 18 Feb 2013; Alexis Ballier <aballier@gentoo.org> + +files/tex4ht-texlive-updates.patch, +tex4ht-20090611_p1038-r2.ebuild: + Add small updates from TeX Live, by José Romildo Malaquias , bug #406045 + thanks, sorry it took so long