404 Error when using downloadFile()

I am trying to scrape images from a website. Normally the image is seen through a java applet...According to the transaction logs, the site takes in several GET parameters including an image ID, then a .jar file (assuming this is the applet) is downloaded along with a few other files and finally the image is downloaded. Visually, I see the applet load, and then the image appears in the applet. When I try to download the image directly however, without first visiting the page with the applet, a http 404 error is returned. If I visit the applet page first, then I can download the image with no problems, however this would be inefficient, if not impossible for downloading large amounts of these images.

I have tried including the site with the applet (and all correct parameters) in my scraping session and downloading the .jar and other files before I try and download the image...essentially recreating step by step how I would normally view the image and make it available for download. However, I have had no luck with this and still receive the error.

Any help would be greatly appreciated.