Nuxeo 5.6 on ubuntu server 12.04

Hi,

normally, nuxeo is not expected to replace a document by another document with the same name. This is the problem I'm facing now.

Take the folder XY with the document AB inside it. Drop or import in this folder a new document with the same name, so new document AB. The expected result should be: 2 documents in folder XY, namely document AB and document AB. What I'm getting is: 1 document AB, with un updated version from 0.0 to 0.1.

Where can I have a look to get nuxeo behave as expected?

Thank you