+2  A: 

By default the Assigned To list comes from the members of the Team Project group called "Contributors". If you right-click the Team Project, choose Team Project Settings and then Group Membership and check the members of the Contributors group. If you can't see it in there try using TFSSecurity.exe:

C:\Program Files\Microsoft Visual Studio 9.0\Common7\IDE>tfssecurity /imx
n:"[TeamProjectName]\Contributors" /server:ServerNameOrUrl

Regards,

William D. Bartholomew (Team System MVP)

William D. Bartholomew
I keep getting "Error: The identity cannot be resolved." with tfssecurity because LOCAL SERVICE is not coming up in the GUI. After I type the command in I get prompted for username and password, but it never authenticates. Any ideas?
Giovanni Galbo
It looks like LOCAL SERVICE is not a contributor (see below). I guess I must have changed a default setting or something.Identity type: Windows user Logon name: NT AUTHORITY\LOCAL SERVICE Display name: LOCAL SERVICEMember of 3 group(s):a [A] [SERVER]\Team Foundation Administratorss [A] [SERVER]\Service Accountse [A] [SERVER]\Team Foundation Valid Users
Giovanni Galbo
Actually, the default list of users comes from [SERVER]\Team Foundation Valid Users NOT [TeamProjectName]\Contributors as I originally stated.This blog post might help you out:http://dotnet.org.za/willy/archive/2008/09/17/tfs-why-is-the-quot-assignedto-quot-drop-down-listing-gazillion-users.aspx
William D. Bartholomew