A user has entered time against a project in the past and later the user is no longer a part of the project team and if these time entries are transferred from Web TimeSheet to Microsoft Project, for that specific time period then the time will not get transferred. Microsoft Project Integration Manager will first read the Project/Task structure and then the assignments of the users in that Project/Task structure and since the user is no longer part of the project/task structure the time entries will not be considered.