Bill, thank you for your details. I understand what you are saying. It appears there may be some problem in Hoster that is worsened by certain hardware/software system configs. I think that may be what is happening here. Clearly, 3.301 works fine and 3.313 doesn't for your mate. That's pretty good proof that something in Hoster changed.
The other fact is
thousands of others have downloaded 3.313 and this is the only Thread reporting this problem. It happens on a very few systems.
Go figure! 
We can search code till the cows come home and not find anything. If we have the problem appear in our testing, we can nail it in a skinny minute. The files you sent up earlier did not re-produce the problem at MTU, so sending more files probably won't either. That's another reason why we all have been saying it is the system config.
We've got a really tight deadline the end of this month that we are working on now. Given the few systems (including your mate's) that exhibit this, I can't shift our focus back to Hoster at this time.
We'll document this and take a look in January at what code changed. We'll compare 3.301 to 3.313, in the code areas that could possibly cause the problem you are reporting.
From the current facts, I expect we will find something deep in Hoster. Just can't do it right now. Sometimes, waiting turns up more folks with the problem and then, one day, a single post contains the key we need to find and solve it. So, we're watching for who else sees this and reports "different" details.
Return your mate to 3.301 for now. That's the only work-around I can offer at this time.
BTW: Ddouglass is not an MTU employee. He is one of our Beta Testers, so he is "closer" than most to what is going on at MTU. He's a fine fellow, and a great technical diagnostician. He has helped many solve problems. I know he's just trying to overcome your and our frustration. He knows MTU hates to have a single problem lurking out there for anyone to hit... and so does he.