To confirm, you see the file start downloading, there is a regular progress bar that works its way across, and then when it reaches the end it goes into the spinning barber-pole lines and gets stuck there. Is that correct?
If so, I'm going to guess that it says "Decompressing Download" underneath the progress bar once it goes into the stuck phase.
If so, the problem isn't the download process, it's the browser trying to decompress the download after it finishes. Try, in this case, clicking the magnifying glass icon on the right side of the browser window to show the actual download file in the Finder. It will presumably look like a 92MB file with a .zip extension at the end. Double click on it and see if it decompresses--if so, the file was indeed fully downloaded and just failing to extract.
If you get an error trying that, post what it is.
Also, if Firefox is hanging on the download, try temporarily disabling the "block popup" feature--I believe the site is being aggressive enough in trying to open a new advertising window when you start the download that Firefox is blocking enough that it fails to start at all. I've seen it happen before.
Alternately, try downloading Opera or Chrome and try one of those.