Images not displaying in Views list

I'm creating a page with a list of product nodes, using Views. Everything is working fine, except my thumbnail image isn't showing up on the page Views list. I'm not sure what's going wrong. My product nodes all have images, which I uploaded using Image, Image Assist (I have tried attaching the image and also embedding the image in the body of the text). When I define the fields in Views these are the options I get for images: Image: Display Image, Image:Image (image_field_cache), Image Attach: Display Image. I have tried all three of these fields and none of them have given me any images. I think I must have something set up wrong-either in my product node images or Views, but I'm just not sure what. I've been playing around with this trying to figure it out for more than a solid day now, I've posted Forum topics but no one has replied yet, I've checked all the settings I know to check on everything else I thought it might be, I'm starting to get desperate..... Any help would be greatly appreciated! Thanks!