my probs where solved by me even though i never used the claimed stealth mode in chips but i created an image of a ps2 game (ISO) then used a small app called WinDip to detect what version your game is (PAL-NTSC) then you will have to add 5 pairs of numbers (hexadecimal). the exact link is this:
http://ultramaxzone.com/2010/01/uncategorized/play-ps2-games-onlinethe-best-post-for-both-original-and-backups-games-with-dnas-error-solved/
and here is a list if online games still in the service but it is and old site:
http://playstation2.onlineconsoles.com/phpBB2/content_gameslist_pl.php
Be careful because the site which has DNAS authentication numbers list will allow you to enter it ones because it will detect your cookies and would only allow you to see that forum another time once you register so as a precaution copy them on a Word file. Also be sure to have blank DVDs to copy the decrypted image file (ISO) to it.
as for the configuration on ps2 i set them on Auto because i use DHCP from IDM so i only set the DNS host as idm.net.lb (after it is set on auto press the triangle to insert that host).
