hi, sorry didn't see this before, if you are posting a question specific to imageflow I suggest you post in the fxplug fx forums as I automatically get emailed there when anyone posts there.
http://www.fxplugfx.com/forum/forumdisplay.php?f=19
the next version of imageflow will have a "display each image only once" checkbox.
for now you need to work it out manually, multiply the number of images in your folder by your seconds per image and then drag your generator to be exactly that length.
hope that helps
Roger
CoreMelt