There is some memory leakage in Premiere Pro that I am hoping that they will fix eventually. It causes problems with larger stills, or large quantities of stills.
Steven
Adobe Premiere Pro 1.5 / After Effects 6.5 Pro
http://www.stevengotz.com
Learning Adobe Premiere Pro 1.5
http://www.lynda.com
Contributing Writer, PeachPit Press, Visual QuickPro Guide, Premiere Pro 1.5