With the incompatibility of iPhoto included with Mavericks and Aperture 3.4.5, Apple release 10.9 without upgrading Aperture. So I'm wondering, what are the odds we'll see a new version of Aperture vs a patch to restore compatibility?
My libraries are merged and both Aperture and iPhoto works fine.
But are you running Mavericks and the Mavericks version of iPhoto?