If you google '12% download timeout on adobe' you will see that a few people including myself are getting this now.
If you google this forum, most likely you will find the alternate download link http://www.adobe.com/products/flashplayer/fp_distribution3.html
Did you try this?
Just ran into this problem on my network. On the page with the yellow "download" link or before, hit the compatability button on the top (looks like a broken page). Then hit download after it finishes re-loading. My guess is that they haven't updated their downloader to work with the features of the new updates of the new browsers.
Since the problem is getting all of the download just go to http://kb2.adobe.com/cps/142/tn_14266.html and download the appropriate zip file of the version you want and then install it. Be careful to use the readme file to decide which files to install for your operating system and browser.
The way to fix it for you is the open IE(Internet Explorer)
Then on the top right corner you see Tools,click on that then choose Internet Options
Then Connection tab then click LAN settings
Lastly Uncheck Automatically detect settings
Then click ok
Now GO back to mozzila firefox and download it
I tried it and works for my computer it said use to say timeout at 7% or 47%
Now its 7% then 8% and onn.
If it works you can brag it to others.
Message was edited by: Mrhelper