Nicolas Frank wrote:
  Hello,
  I have a document created in the blog that has disappears (it happened when
 we were still in 1.6, after the upgrade to 1.7.2 the problem is still there).
 I can't understand why... what rule is following the blog macro to choose
 which document has to appear ? 
Check if the document has an XWiki.ArticleClass object attached to it.
The blog application displays all the documents with such objects. Check
the history of the document to see what/who changed.
  The record is still there in database and I can access
the document with the
 search function.
 By the way, how is the XWD_ID created and why does it has sometimes a
 negative value ? 
It's a hash of the document name (+language, if it is a translation).
--
Sergiu Dumitriu
http://purl.org/net/sergiu/