I'm not sure what the actual problem is, but there's a workaround in this case. Maya ships with plugins for a number of programs that will enable them to read the .iff format. Photoshop is one of them. I don't know exactly where it is in the structure, but you should be able to find it if you run a quick search through the maya help files. I don't know if AfterEffects is on the list, but since you should be able to convert them to something else through photoshop, it doesn't really matter....