My KDE 4.6.5 post from a few weeks back had a few comments about a non-working kcalc. Also, the KDE release team updated all the language tarballs for KDE 4.6.5 – after first renewing the broken ‘nl’ sources apparently the other language sources had issues too.
So, I rebuilt all the KDEI packages (the language packs) using the new sources. And I rebuilt the kdeutils package using several patches for kcalc.
Go get them. If you had the aforementioned issues they might be solved by these updated packages.