latex2html bundles an old version of the tex url package (url.sty) whereas texlive-latex-2008 includes an up2date version. Unfortunately latex2html gets installed to /usr/share/texmf/ which should actually be /usr/share/texmf-site/. So what happens is the old url.sty is naturally found first and will be used instead of the newer version which brings more features. This breaks some functionality with bibtex8 as well as biblatex (which is not yet in portage). It took me the better half of a day to figure this out and I may have to grow back some hair on my head again. ;-) Reproducible: Always
Not sure whether latex2html or texlive-latex ebuild needs to change (or both), luckily the same devs are handling both packages...
I've removed url.sty from latex2html-2008 as all our tex installs alread provide it; should be fixed now. thanks for reporting