After moving a branch from one TFS server to another I got the error:
"The item \$TFSProject\mylocation\myfile.cs does not exist at the specified version".
First I thought the Check in was buggy and went to another machine. And like a miracle it worked there.
Then I googled and found out that this usually relates a messed up workspace.
Especially the following link was very interesting:
http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=2367863&SiteID=1
But this was not my problem.
I had two Visual Studios (2008) open.
Inside one instance I used the Team Explorer to disconnect from one TFS server and connected to another TFS server without closing the second instance or restarting VS.
I guess the TFS integration in VS got confused and was choking.
So I restarted VS and everything went back to normal.
Sometimes a simple restart does the trick. But at least I learned about how to delete your workspace :-)
Tom