Just posting this because I ran into this problem today and searching Google/Live didn’t help (returned a site where you have to pay to get answers? I guess the http://www.stackoverflow.com model doesn’t work for them :)

In any case, the problem I ran into was that when I started my Hyper V image, it would pause all the time about 30 seconds after I started it. It turns out that the issue is that if you are low on disk space on the real drive that your VHDs are in, Hyper V will pause your image. So if you see this, just clear up some space, and Hyper V should be good to go :)