[Black Tiger]

Oke, got the error for you, when running it in the generator it will give no error. The error is in the output.
When I look with editpad lit in the sitemap_4.xml the last line is this:

<url>
  <loc>http://www.satellitefun.org//index.php?pageid=googlesearch</loc>
  <priority>1</priority>
  <lastmod>2008-02-18T14:43:56+00:00</lastmod>
  <changefreq>daily</changefreq>
</url>
</urlset>

You won't see an error in there, but when looking with a browser to the xml file you will see this, and now I'm glad you understand Dutch.

- <url>
  <loc>http://www.satellitefun.org/bbs/poll.php?do=showresults&pollid=5</loc> 
  <priority>0.6</priority> 
  <lastmod>2008-02-04T22:45:01+00:00</lastmod> 
  <changefreq>daily</changefreq> 
  </url>
- <url>
  <loc>http://www.satellitefun.org/bbs/poll.php?do=showresults&pollid=6</loc> 
  <priority>0.6</priority> 
  <lastmod>2008-02-04T22:45:01+00:00</lastmod> 
  <changefreq>daily<De XML-pagina kan niet worden weergegeven 
Kan XML-invoer niet lezen met opmaakmodel XSL. Herstel de fout en klik vervolgens op de knop Vernieuwen of probeer het later opnieuw. 


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Er wordt een puntkomma verwacht. Fout bij het verwerken van bron file:///D:/temp/Rar$DI00.563/sitemap_4.xml. Regel 101289,...
 
  <loc>http://www.satellitefun.org/bbs/downloads.php?do=cat&id=1</loc>
------------------------------------...
SPAN class="m"></changefreq> 
  </url>

As you see a lot of crap in there.
When google sitemaps has this file it also says it has a parse error.

When I start the addon without the seo and without being logged in I get this error:

Fatal error: Call to a member function query() on a non-object in /home/satfun/domains/satellitefun.org/public_html/bbs/vbseo_sitemap/addons/vbseo_sm_downloads.php on line 21

And line 21 is the first line of the script which starts with $mods. However, I'm not logged in then and I started the addon stand-alone by visiting the file in the url, so maybe it has nothing to do with the problem.