I also tried "overwriting" the photos directly on the movie timeline, but it seems better if I have the movie on one timeline and fade in/out the photos on another timeline directly below the #1 timeline.
I have about 50 photos I need to add into about 30 minutes of footage. Any suggestions? PD9 64 bit, ThinkStation W7Pro, XeonW3520@ 2.67ghz, 12gb RAM, Nvidia QuadroFX1800, Two 1TB Drives.