What was the debate at the Reformation concerning "non extra carnem" vs. "extra calvinisticum"? In the debate concerning the "hypostatic union" and the "kenosis" the Lutheran church stood opposed to the majority position. I can not seem to find a good resource to explain the distinctives of the two sides of the issue. 

As far as I am able to understand it, the debate was over the concept of whether or not the infinite divine nature of the Logos was contained or not contained in the finite body of Jesus. 

I believe the majority opinion was that the finite can not contain the infinite, following the Chalcedonian formula of no mixture of the two natures. And the Lutheran belief is that the two natures cannot be sepparated. 

I am confused as to the Latin "non extra carnem" not without incarnation. What is it that is "not without incarnation"? Also how does all of this relate to the "kenosis" or emptying (Phil.2:7) during Christ's earthly ministry as compared to after the assention? What is orthdoxy and when do we cross the line into heresy?
I'm not sure I understand the specifics of the issue exactly, but the Essay Library from the Wisconsin Evangelical Lutheran Synod often has good resources on questions like this.

A quick search turned up two essays that seem to speak to the questions:

http://www.wlsessays.net/files/PetersCalvin.pdf

and

http://www.wlsessays.net/files/SchulzGenus.pdf

[EDIT]

Sorry for the format of my initial answer. I went through the first document a bit more carefully and it looks like the difference between the Calvinists and Lutherans was about how Christ's body was present in the Eucharist.

From the first article:


  Calvin’s main objection to the Lutheran understanding of the sacrament
  was that the Lutherans understood the body and blood of Christ to be
  present substantially...and would allow no figurative understanding of
  Jesus’ words of institution. The Lutherans believed that Christ’s true
  body was able to be simultaneously present on many altars by virtue of
  the communication of attributes...and therefore truly present under
  the physical elements of bread and wine.