The ebuild for K3B (at least 0.12.14) is currently not using LINGUAS variable in portage and it compiles *ALL* language in k3b-i18n. Thus is breaking gentoo philosophy (by compiling all).
Please, read the ebuild before filing bugs.
Eh, I see what you mean now, sorry. It just ignores the set LINGUAS....
No problem, I do read the ebuild anyway, it enables ALL linguas, and doesn't take into account the LINGUAS variable in make.conf and disabling all the rest. This is better explained :)
Thanks for reporting, I've fixed this now in 0.12.16.