Problem running certain PSX games on my PS2 Slim

[JKKDARK]

I have NBA Shootout 2004 and NFL Gameday 2004 (both PSX versions). I'm running them on my PS2 Slim but I have the same problem on both games; after the intro, a symbol like this one (http://www1.istockphoto.com/file_thumbview_approve/400212/2/istockphoto_400212_shoes_banned.jpg) appears in the screen (and it seems there are also some words but I can't read them). Then I can't do anything, the game freezes.
Is it a problem with the compatibility or what? The discs are not scratched. Thank you.

[VampDude]

Have you tried:

Turning the PS2 on with the lid up (or with no game), and on the menu pressing the triangle button to enter the Version Information screen. When there press triangle when highlighting Playstation® Driver, then change the Disc Speed to Fast and Texture Mapping to Smooth.

I don't know if this will work for you, but it works for most've my PSX games.

[JKKDARK]

wow it works now, thanks :D