Image Assist Does Not Insert Images. Period.

Drupal: 6.14
Image Assist: 6.x-2.0-alpha4
Image: 6.x-1.0-beta3
FCKeditor: 6.x-1.4

I've coppied over the modules/fckeditor/img_assist_fckeditor.js file to modules/img_assist/img_assist_fckeditor.js and I have also checked the box in the html input format properties (a step which was nowhere to be seen in the documentation!). But when I try to insert an image via Image Assist into the content by pressing the "insert" button, the popup window goes gray and there is a darker gray bar at the top which reads, "Properties: Change how the image is displayed." and a "Start Over" button. I thought, "Do I have to upload the images to the server beforehand?" I tried placing images on my server into the body's content and it still didn't work, but even if it did, that would defeat the purpose of having people conveniently upload their own content. I can click and drag the image out of the Image Assist pop-up window, but it looks as crumby as if I had used the default FCKeditor inline image insert button. I've re-downloaded the module, but it still will not put things into the content... I am at a loss of things to try.
This is really frustrating, and I can't find any help anywhere on this! I was told this was a good module for inline images, but if I can't figure out what's wrong, I'm just going to scrap the idea of using the entire Image module.