When reading my RSS feed with the Thunderbird feed reader, some entries are duplicated. Google Reader does not have the same problem.
Here is the faulty feed:http://plcoder.net/rss.php?rss=Blog
There is a problem, but where?
I added a GUID, but the problem remains. Other feeds do not duplicate like mine, so I will do rework on this module and replace this old good code.
Conclusion: I completely reworked the RSS generator code, and it's OK. I think I was using a very old version of RDF.