I bought the same RiTEK DVD-Rs as crippy bought which have “NSP” letters near their hub 2 weeks ago. I tried to Burn some of them and found that all burnt quality were quite excellent. But I don’t know how long can they last. I scanned them again after a week, I couldn’t find any difference so far. The scan results still remain excellent.
In my experience, bad RiTEK tends to have some quality difference even after a week or have problem in the first burn. I believed that the DVD-R media made by RiTEK that we could obtain at today’s market already solved the problems like you experienced. But it seems that you got a bad batch of RiTEK very recently. Did you buy them at special discount price? If so, the seller knew about the problem of the discs you just got and down the price deliberately like a clearance sale, I thought.
Anyway, RiTEK has been deemed to be still dangerous. If you want to avoid further trouble, you should try Taiyo Yuden. If you want to enjoy gambling like me, it may be worth trying RiTEK.