switters, this could be an issue with the date/time on your webserver. Even though the images are publshed, if they aren't set to display until a date in the future, you won't see them unless you're logged in as admin. Though, I've just checked your site and there are indeed four thumbnails showing up.
To Everyone: This thread really should be reserved for comments relating to the DELICIOUS v1.0, template. If you're having a problem with pixelpost in general, see if you have the same problem with the simple or horizon template. If you do, then start a new thread in the pixelpost help forum. Posting your problem here means that only people who are interested in this template are likely to read it. Posting in the help forum means that someone who is willing/able to help is more likely to see it.