NEO what? If it's NEO4 there have been reports of slow loading.

Otherwise the symptomes are those of laser calibration. You should check the offending PS2 media because calibrating for one case can screw another! Perhaps go to site ####://www.cdrinfo.com/software/clonecd/index.shtml and download CDCHECK from the software section and look at the CDs involved. The article to which I've pointed you is also interesting for other reasons.

Keep us posted.