Apple has released a sizable update for its iPhoto photo management software for OS X Lion version 10.7.4 or later, which, despite weighing in at around 600MB, offers a relatively small number of fixes to the program. According to the update's Web page, it addresses two problems with importing and migrating albums into iPhoto.
The first issue is when albums are migrated from Apple's now closed MobileMe gallery, where photos are moved to a folder called "from MobileMe," and the second issue is a problem with iPhoto hanging when upgrading older versions of iPhoto libraries.
Because the issues fixed by this update are with importing, if you are using an older version of iPhoto and plan on upgrading to the most recent version, or if you are migrating to a new system then you might consider first ensuring iPhoto is fully up to date before importing your photos from the previous version.
The update is available through Apple's Software Update service, but can also be downloaded from the iPhoto 9.3.1 update Web page. As always, be sure to fully back up your system before installing this update, to ensure you have a restore option in case the update causes problems with your setup.