Thank you for your help.  I appreciate the suggestion about paying for a subscription but I don't see how that would affect the problem I am having.  While I have no problem supporting the site, and in fact would be happy to do so, I am hesitant to do that until I am sure I can actually get the files I am interested in.   That being said, I did some more experimenting this afternoon. 
  
I disabled everything with McAfee including all virus scanning and my firewall.  I disabled every plug-in and add-on in Firefox and tried to download the following file via the download mirror: 
  Vietnam 1984 1.1:  http://combatace.com/files/download/1975-vietnam-1984-11/page__mirror__1 
  
It ran at an average of 150k until it hit 194 megs then stopped.  The file was 215 megs in size.  I then tried some of the files previously mentioned via the regular download links and they ran at 600k but all stopped as before.  What is so aggravating is that I downloaded numerous files from the site up until a week ago and had no problems.  I can't remember what the biggest successfully downloaded file was but I think it was perhaps 20 or 30 megs.  Maybe the larges files of these campaigns are the problem, I don't know...  Also, it seemed that before I could download 8 or so files per day but now I am only getting 3-5 file attempts before I get the exceeded download limit for the day.  This makes me think that a download manager is still running but I didn't see a manager listed in the Firefox add-on page.  Is there something else I can check to make sure I am not having a problem from a download manager? 
  
Do you know if any of these files are available on any other websites so that I can check and see if they work from a different server?