After reading so many talking about how google handles this format, I ended up going to Google Webmaster and see how it handled mine.
Actually, I don’t have warnings or errors…
However, Google provides a way to show, side by side, the number of links submitted in the sitemap vs the links they’ve indexed.
They also show this information as a graph, showing variations over time.
Since 14/Apr (when I’ve updated to the new version of the plugin) the “indexed” pages go down to zero, and it just shows the number of pages submitted in the sitemap.
Definitely Google as issues handling this format.
Meantime, I just reverted all websites to version 3.4.1 of the plugin and will hope the author reconsiders the format or at least provides an option to keep the old format.
cheers,
Miguel