Latest update to kde-meta.eclass by greg_g broke almost all kde-3.4.1 related digest files. For example: digest.partial 1 digest-ark-3.4.1::kdeutils-3.4.0-3.4.1.tar.xdelta I can forward you a complete list, if you need it.
Right, the typo fix implied that all the digests had to be regenerated. Done now, USE="kdexdeltas" should be finally working.