Dual Layer DVDs

I’am having a lot of probs burning dual layer dvds +R none of them work in
my dvd player or on my PC.
Writer NEC 4550a 1.07 Firmware Flashed a last week 1.06 would not work either
Nero V6.6.0.12
Panasonic S49 DVD Player

Hope someone can shed some light on where i’am going wrong

You don’t say what brand of dual layer dvd’s you are burning, but from everything I’ve read, the only ones which work fairly consistently, are the verbatim brand. You also need to go to www.videohelp.com, and search in the dvd player area, and see what type and brands of dvd’s your player will accept. They are all different.