on the DVD disc written : 16x. Is it OK ? (The buffer slow down several times, but the burn succeed - I got a message)
What burning software did you use? Your burn software should have something like "Verify data after burning" if that was checked you should be good to go
I like to use nero discspeed to check a burned disk. another one I liked was called K-Probe but havent used it in a couple years
Try to burn at slow speeds at x4, x5 . It will take little more time , but burned disks will be more reliable , that was advised at Doom.org years ago, and that's what I do.
I normally burn at half the recommended disk speed i,e, x16 speed DVD burn at x8 speed, especially on dvd video disks.