Hi raf1870,
Since you are seeing the HTML Uploader page when you click the "Select an Images" boxes on the Auctiva lister page, I suspect you must have your default image selection view on the one-page lister set to "upload". You can check this out by clicking the "Account Settings" link under the "My Account" tab within your account and looking for the "Default View when Selecting Images on One-page Lister" drop-down menu in the "Image Management" section.
If you select "thumbnail" or "list" from the "Default View when Selecting Images on One-page Lister" and then save your changes, you will see the option to select from the images you have already uploaded into your Auctiva account when you click the "Select an Image" boxes.
If you have any additional questions or concerns, please feel free to contact our customer support team using the web form on the following page:
http://www.auctiva.com/help/requesthelp.aspx-Mike