Apple released a minor update to Aperture a few minutes ago, improving compatibility with the importing process of iPhoto libraries and a number of reliability improvements for brushes. The new version is labelled 3.1.2; Aperture 3.1.1 was released in December.
About Aperture 3.1.2This update improves overall stability and performance, including specific fixes in the following areas:Importing iPhoto librariesReliability and responsiveness when using brushes to apply adjustmentsReconnecting referenced master images
