Hm... This sounds like the problem I'm having. This might not work, because it stopped working for me, and now my PS2 flat out doesn't read discs, but go into the browser, then click on the memory card. Let it load up, then exit out, and you might be able to click on the disc.
But on the same tangent, my PS2 will let me click on discs in the browser, but it'll show the "Playstation 2" screen, and then return me to the browser. It had just been doing it with GH2, but now it does it with everything... I think the drive is just screwed up, but, any help would be appreciated.