We are talking about land here. Not personal posessions. And no it's not antithetical to libertarianism to understand that the only way you can trade real estate is in the presence of government. The only way one can own land is if there is a piece of paper that says he does. Otherwise he is simply making a claim. One never really owns land.
One can chose a territory and defend it. But one doesn't own land. That is a modern invention. If you owned it, you could take it somewhere else.
Registry of deeds doesn't have to be a function of government. Since in modern times a government is always around, it becomes a convenient registrar, but it doesn't have to be this way. In order to defend a title to the property any unambiguous and credible evidence would do; it could be documentation kept by a private party or simply fences, monuments and other artifacts traceable to the owner present on the property itself.
In any event, the need for a registry doesn't translate into a need for a national in scope government setting restriction on foreign ownership.