As you probably know when you're reading this question, an .odt file is just a .zip file containing some folders and .xml files.
I used to appreciate this, for I could make a document with keywords in OpenOffice (2010), and generate for example different documents with address data online using a PHP script.
The interesting file is content.xml, where you can change the contents of the text. Afterwards, you zip everything together and you got yourself a working .odt.
However, when I make new templates using LibreOffice (2012), the resulting document is corrupted and Writer will try to recover it, but fails and leaves me with an empty document.
The file structure of the .zip (.odf) file looks the same to me. It doesn't look like something has changed, but it must have. Funny thing, when I use the 2012 content.xml from the corrupt document and zip it in a working 2010 document, it suddenly works again.
What has changed in the document format? Is there a way I can still 'automate' my files this way? Why would they change something that is nothing but nice for super users?