It would seem that the "Container" in that context is the login control not the repeater. I don't know what is available on the "Container" object, but perhaps there is a parent that would get you back up to the repeater and then it would work.
I haven't used the login view so I'm no authority on what you can or can not do with it. But it would seem to me that using a login control in a repeating control is out of place. Why are you using it there, what are you trying to achieve?
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Peter