I have the same problem in Yahoo games. Internet Explorer will stop working.  I've done extensive troubleshooting of this and it is 100% caused by the AD Choices video ad that plays on the side of the games main screen or on the side of the specific game being played.  

In my case it has been a hair products ad.  After the ad runs for either 15 or 30 seconds I assume it should move to another ad but it does not.  The flash player goes white and IE crashes.  If I pause the ad so it doesn't have the chance to fail, no problems.

If when I connect to Yahoo Games I get one of the non video ads (such as Evony or Cici's Pizza), there is not an issue.  It is only video ads that cause the problem.  This started about three days ago.  It is not a problem with my system, pop ups or anything of that sort.  It is Yahoo's problem.  Please fix it.