sorry to tell you this, but you have a crappy drive.

do a web search for DS8AZH, and there are many negative comments. even several reports exactly like yours.

i would not put too much effort trying to burn with this drive. even if you are successful i would trust the results.

so first id try lowering the burn speed, go 6x then 4x and 2x if this doesnt work with the verbatim 16x dvd+r then you could possibly try some -r's. but you may have to just try every media you can find until you get lucky. some report being able to burn on cheaper media.

it would just be easier to get an external lite-on dvd writer.