According to notes provided with the update, iLife Support 8.3.1 provides system software components shared by all iLife '08 applications. While Apple doesn't go into detail on what was fixed they did say it addresses a number of minor issues.
The update also improves overall stability of the applications. iLife includes iPhoto, iMovie, GarageBand, iWeb and iDVD.
The update can be downloaded from Apple's Web site.
This story, "ILife Support Update Improves Stability" was originally published by Macworld.