I have just signed to forum to post the EXACT SAME PROBLEM (xbox 360) with the game hanging once the summoning begins.
After searching the net in relation to this issue, i found that it was 1st highlighted back in jan 2010, and we are still waiting on a fix............simply not good enough. I fully understand that the problem is only encountered by the minority but it basically seems as if the software developer is ignoring all requests for a fix, as they replied to a post early 2010 saying they will look into it..............hrmmmmm and i see the same response on this forum......................
Suppose the people that spend their well earned / saved money on this game are not important enough for the developer to try and solve the issue.....................always a typical response from game developers when folks still keep buying the product, but we live in hope that this issue WILL be resolved, and not just to keep getting fobbed off that it is being looked into...............
These scenarios just make me sick, when the responses are just to put people off, delaying tactics, knowing that the issue will not be solved, hope the developer proves me wrong.