I think I need a little more context in order to fully help out. What pages specifically were the images not working? Were you putting them into the image part of the infobox or just on the page in general? Were they not functioning in the sense that the images are not showing up at all, or just not showing up in the infoboxes?
If you want to know how I do infoboxes, I specifically edited the Birdo Egg page as a reference point. Let me know if that's helpful for you.
If any other information is needed, I would be glad to provide it for this situation.