Sorry for the multiple messages - I did a little more looking at it tonight and it appears that some of my images are 24 bit, but those images are still showing up and this is the size I have always used. Would this just newly become a problem? I tried adjusting the size just in case and it didn't fix the problem.
Attached is a similar file that does work as intended. Can you see something that would be causes the lower 2 pictures to not appear each time? experimental task 1000ms.csv