TFS集成工具 - 历史记录中的用户错误

I have migrated several projects from TFS 2010 to TFS 2012 in our domain. I have a team project where after migration when I check the history in Visual Studio my user account is on many changesets. This is because my user account is running the TFS Integration Tools. What I don't understand is why it cannot determine the right user from the source team project for some users and hence puts my user account on the changesets in history and for some users it has no problems at all. I have migrated several projects from TFS 2010