Hummm, I investigated this special case, and seems that it is a duplicated, probably caused by the import from phpBB. Those are 39 cases aparently, but I don't think this is what is causing the sitemap to generate the url with the ID.
What is actually generating a lot of errors are private links on the site, for example:
http://forum.antinovaordemmundial.com/ne...=27555,404 (Not found),5 pages,14/08/2011
http://forum.antinovaordemmundial.com/ty...d=2447,404 (Not found),1 pages,14/08/2011
http://forum.antinovaordemmundial.com/ca...r=1935,404 (Not found),1 pages,14/08/2011
http://forum.antinovaordemmundial.com/ra...c5556d,404 (Not found),4 pages,14/08/2011
http://forum.antinovaordemmundial.com/se...d=2222,404 (Not found),3 pages,14/08/2011
http://forum.antinovaordemmundial.com/pr...d=2443,404 (Not found),1 pages,13/08/2011
http://forum.antinovaordemmundial.com/se...d=1484,404 (Not found),1 pages,13/08/2011
Some print threads fail on google too, although I can reach them on the browser:
http://forum.antinovaordemmundial.com/pr...hp?tid=610
Other errors by the crawling seems to be on threads that have brazilian especial character on it:
http://forum.antinovaordemmundial.com/Fo...ários,404 (Not found),3 pages,12/08/2011
But the sitemap seems to have encoded that correctly:
http://forum.antinovaordemmundial.com/Fo...%C3%A1rios
Is it an error of google crawler?
That said, I believe I am missing some configuration on that robot.txt to disallow searches, repliy button and other internal navegation links to be followed by google crawler. How can I do that?