Retryrtrytrrutryturu,
Your problem is the way you're forming links:
http://www.qualitylamps.eu/Sony-VPL-...ml?&manid=6150 (works)
http://www.qualitylamps.eu/Sony-VPL-...tml?manid=6150 (page cannot be found)
In the first link you have a ?&manid=6150, which doesn't make sense but is working because your server is throwing away the ? and looking at just the &manid=6150. In the second one, you just have a ?, which normally would be fine except there's already an ? in the URL that you don't see - CDSEO covers it up. that Sony-VPLxxx.html actually contains "?productid=482378", CDSEO's script rewrites it as such behind the scenes - so you want to follow any .html with a &variable=, not ?variable=. Make sense?
Edit - just tested it on your site, just using &manid=6150 wasn't working either, so I think you need to look at your .htaccess file to see if there are any rewrite rules causing problems.