My ksplash themes in /usr/kde/3.5/share/apps/kdm/themes/ aren't recognized by kdm-3.5.6-r1 (testing). I downgraded, and all the themes are listed in the kdmtheme dialog of kcontrol again. I think this has something to do with the removal of some patches (as stated in the Changelog on packages.gentoo.org). PS: It's not possible to install new themes with kdm-3.5.6-r1 at all for me. Reproducible: Always
Typo in my first post: It's a "kdm theme" not a "ksplash theme". Some more details: the kdm theme dialog in kcontrol shows only the active kdm theme set in /usr/kde/3.5/share/config/kdm/kdmrc (Theme=/usr/kde/3.5/share/apps/kdm/themes/circles, e.g.). With kdm-3.5.6 it listed all the installed themes.
The patch added with -r1 is trivial and definitely has nothing to do with your problem. Also I installed kde-misc/kdmtheme and it works fine, here.
*sigh*