i want the main page of my site to display the thumbnail images in the excerpts, but when I click "see more" I want the image to be larger (full size). How do I do this?

I have all my main page's posts set as excerpts, and when I insert the image into each post I have been selecting thumbnail.

nothing to do with the theme, this is strictly WP.
add an image to the post, then in the 'Feature Image' section hit the set featured image and pick the same image

Hmm it still doesn't seem to be working. Here is what I did:

- Added the image as a thumbnail to the post
- clicked featured image and added the same image as a featured image

My post still shows as a thumbnail when I go the post's page. Is there something else I am supposed to do after I set the image as a featured image to make it enlarge when I go to the post's page?

You need to add the image to the post at the large size you want. The featured image will show as the thumbnail. By adding to the post as a thumbnail you have the same size for excerpt and full post.

Okay, so I added the image to my post at the large size (as well as inserted it as a featured image) and now they both show at the large size..there is no thumbnail. Is there code I am supposed to write somewhere so it shows as a thumbnail on my main page?

what version of Atahualpa and WP?
wjhat is the url?
if on 3.6.7 - did you apply the patches? (if not you might want to upgrade to 3.7.0)

I have a similar problem. Both the thumbnail and full images shows in full posts and in excerpts.

http://mostpopularjewelry.com

Alvin: please explain in detail exactly how to see the issue at your site.
are you using any plugins that could be effcting it? did you try shutting ALL the plugins off?