Thomas, we've got a bug
http://72.3.250.100/show_bug.cgi?id=5367
that sounds somewhat like what you are seeing. But we have not been able to reproduce it.
This bug says that the confirmation dialog does not have "yes" enabled. Is that what you're seeing? If not, what are you seeing when you click "yes"? Does the admin app just hang? Also, what browser are you using?
Thanks.