If you get an exception saying the directory name is invalid when browsing the change sets from the automaton dashboard for a build type, then ensure you apply the permissions as listed in the below fix on the automaton web site.
Exception: The directory name C:\Documents and Settings\User\Local Settings\Application Data\Microsoft\Team Foundation\1.0\Cache is invalid.
If this exception is received, fix it by giving either ASPNET (WIndows XP) or IIS_WPG (Windows 2003) read and write permission on the Cache folder.
http://www.codeplex.com/automation/Wiki/View.aspx?title=KnownIssues