Update page adding a second file extension when new image uploaded

The insert page works fine, but on the update page, whenever I upload a new image - whether it's a new or existing file name, the image name in the database always show an extra ".jpg" (imagename.jpg.jpg). I'm pretty sure I have all the bindings correct. In the Upload behavior, the file name is bound to the form file field, and the hidden field is bound to the recordset image column. In the Update behavior, the image column is bound to the UploadStatus - Server File Name.

In the previous screen, the dropdown is set to "Overwrite" if file exists - I have not tried to change this as it occurs even with a new filename.

Any ideas? Everything still works fine whereever the images are displayed in the site - eCart, but I'd rather have it not do this.