"user already been assigned a desktop.." although not true

Hey,

I came accross a problem on our Vmware View 5.1 deployment.

When trying to assign a desktop to specific users, i get an error saying that "the user <username> cannot be assigned the selected desktop because this user has already been assigned ownership of a desk top in the pool <poolname>"

Of course this user is not assigned, well not visibly, to any desktop in the pool.

Appreciate any help.

Chen Kasirer.