Problems Burning CD-R Media

This probably sounds stupid, but I’m having serious problems burning CD-Rs on my newer burners (Samsung, Lite-On, and Optiarc models).

I’ve tried CDs from different Taiyo Yuden and Ritek spindles, but transfer rate tests keep producing these kinds of results (see below; discs were written from16X to 48X). Also, some of the older media definitely worked fine on older hardware since TRTs from discs burned 5 years ago show smooth curves.

OTOH, quality scans look great, especially for my Verbatim Pastels…