AML and AML-001 discs are made in Hong Kong. They are some the cheapest discs out there and are definitely not the best stuff you can get. The 4163B does suport both AML and AML-001 media codes though so they should burn in your writer. It might just be the discs at fault. Try getting hold of some better quality discs like Verbatim/Mitsubishi (made in Singapore or Taiwan only), TDK or some Taiyo Yuden media (mostly anything with media code YUDENT00-T02 for DVD+R and TYG02 for DVD-R but only when made in Japan).